When Michelotti’s sharp-suited TR4 was unveiled on the Triumph stand at the London motor show in 1961, the car looked thoroughly modern, especially when compared with the TR3A that it replaced. But the reality was that under the skin the car was still a TR3A – little more than the outer panels were new.

Despite this the TR4, and TR4A which succeeded it, were among the fastest affordable sports cars on offer throughout the 1960s. Cheap to buy and run, the cars’ road manners left room for improvement, but as stylish transport they were pretty much unbeatable.

Triumph repeated the trick in 1969 when it unveiled the TR6, which was little more than a reskinned TR5 (itself a rebodied TR4), but it had a lot of people fooled. Even with the mechanicals, main structure, doors, chassis and windscreen carried over, the car looked fresh enough to appear new. It was also the last of the true TRs in the eyes of many enthusiasts, yet it’s still often overlooked by those wanting a proper British sports car.

If you fancy a post-sidescreen TR, bear in mind that TR5s are more sought after than TR4As, which in turn are more sought after than TR4s. The TR5 is by far the rarest and restoration projects are very hard to find. Even tatty runners aren’t easy to source so expect to pay £6000 upwards for something that needs work. The best TR5 fetches around £20,000 while top TR4s command £13,000 – the nicest TR4As are worth around £1000 more. TR4 and TR4A restoration projects typically command £4000, while you can expect to fork out £7500 for something decent.

TR6s are worth similar money to the TR4 and TR4A, with restoration projects starting at £3000, and something roadworthy costing around £7000. Good cars will fetch £10,000 while tip-top examples will command up to £13,000. However, these prices are all for genuine right-hand drive cars; knock 15 per-cent off if you’re looking at an ex-US car that’s been converted from left-hand drive.