Behind the scenes at Lamborghini's vast archive

But there is still plenty to do. The ‘truth’ Ronconi speaks of sits at the heart of the work Polo Storico undertakes when it isn’t forensically restoring cars like Miura SV chassis #4846 – the wondrous, perfect green machine pictured above – or making historically accurate spare parts. This work involves the awarding, or sometimes the withholding, of prized certificates of authenticity, which cost up to €10,000 (£8900) but can mean rather a lot more than that to an owner or prospective purchaser.

“Twenty-five years ago, you could find a Miura hidden behind other used cars at a dealership,” says Ronconi. And he isn’t exaggerating. Even in 2005, an unexceptional but sound SV sold for just £176,200 at Bonhams; today, a similar car would set you back around £1.5m. And alongside its current status as the most valuable car ever to wear the bull crest, Gandini’s masterpiece is also the model that causes the most severe certification-related headaches for Ronconi and co.

“They are the hardest. Some owners state that the modifications from early P400 or S [specification] to an SV have been done at the factory,” he says. “This is, in the majority of cases, not corresponding to the truth.” The chuckle as he says this gives away his love of the job: “Lamborghini did some upgrades on some cars – cars that had been heavily damaged – but we don’t have the data.” And the supposed word of the chief tester at the time, heard third-hand through your cousin’s friend’s gardener’s neighbour, isn’t going to convince someone like Ronconi.

Strictly speaking, even an endeavour as innocent as fitting SV wheels to an otherwise pristine P400 or using 215-section tyres to improve the handling (an early Miura uses 205-section rubber) is enough for Lamborghini to withhold the documentation. Harsh? Perhaps, but where else do you suggest they draw the line? That every different model has similar idiosyncrasies makes the job an investigative minefield.

Which brings us to the Comitato dei Saggi (the Committee of Wise Men). This intimate group meets ad hoc to debate and determine originality when the subject matter strays beyond even the considerable expertise of the archivists. It passes judgement in more complicated cases: for example, one concerning the front clam of a crashed Miura – one that was not restored by Polo Storico and that seems to have a repunched VIN on the new panel. Certification can be awarded to a car whose engine and, say, differential or body have differing numeric identities but are nevertheless each original, but you need to know your stuff to make that call.

The Comitato dei Saggi therefore consists of Lamborghini CEO and former Ferrari Formula 1 boss Stefano Domenicali; Lamborghini chief technical officer and father of the Bugatti EB110’s quad-turbo V12, Maurizio Reggiani; chief engineer for the Miura and long-time global motorsport tsar Gian Paolo Dallara; Mauro Forghieri, an engineer of extraordinary breadth and talent and the man to whom, aged just 26, Enzo Ferrari entrusted his entire racing operation; and the former head of Lamborghini’s offshore programme, Mauro Lecchi.

It’s a jaw-dropping line-up, for sure, and having your car assessed by the gang must feel like taking your driving test with Jim Clark in the passenger seat while Alain Prost and Lewis Hamilton confer in the back.

Ronconi now takes a moment to dig out some extra special paperwork, starting with the build sheet of the very first 350 GT development car. It’s truly extraordinary. Hand-measured cylinder tolerances are scribbled down, as is the 46 hours this V12 spent on the bench and its 6500rpm ceiling. We can read that it used Borgo pistons and an alternator from Bosch and that the compression ratio was a fairly conservative 9.5:1. These sorts of artefacts form the foundation of the archive and are gold dust for the archivists. “When I read some data made by the engineers – Paolo Stanzani, for example – then it means I’ve found a treasure. [We have] the very first testing reports of the first Miuras – Bob Wallace’s and Dallara’s thoughts. It’s just a few papers, but once you read them…”

Ronconi trails off, but his thinking is obvious. Polo Storico has arrived in the nick of time. This archive will soon find new premises, but for now there’s not even proper atmospheric control in the room where all this delicate paperwork is stored, and for years Lamborghini was frankly negligent, allowing its latest cosmic wares to shunt the marque’s heritage into the shadows. Yet Dallara and Forghieri are still only a phone call away, despite their pencil annotations appearing right here on diagrams that represent ground zero for the supercar as we know it. This realisation is as profound as it is humbling, and it seems that Lamborghini is finally seizing the opportunity to get its house in order.

“Okay, gentlemen” is our cue. For Ronconi, our stay represents 30 minutes he’ll never get back, but for us it represents an intoxicating insight into the Lamborghini time machine. As for the colour of that Diablo, the correct hue will be identified by a colleague in the paint shop; a colleague who has worked in the paint shop since the days of the Diablo, who possibly painted that very car and is now mere weeks from retirement. Like I said: it’s all happening just in the nick of time.

The other machines

In addition to its historic road cars, Lamborghini will provide a white ‘Historical Authentication’ dossier on, well, anything that has ever carried one of its mighty engines and is period-correct, including these eclectic machines…

Lotus 102 1990: Known mostly for its livery, the 102 is the only Lotus ever to use a 12-cylinder engine – and what an engine it was. For an F1 application, Lamborghini tuned its 3.5-litre V12 to deliver 750bhp and spin to 14,000rpm in race trim. Not that it ever powered the team to victory; driver Derek Warwick eventually described it as “all noise and no go”.