All of which is why these Frontline LE50s, 50 of which will ultimately be made (26 ordered so far) and which celebrate a half-century's passing since the B's launch, have a seam-welded bodyshell (brand new, from British Motor Heritage) with extra reinforcing gussets and a heavily re-engineered suspension system. Visible seams are spirited away and the rear side window apertures get bigger flanges, to take seals better able to banish wind noise.
Suspension is still double wishbones at the front, but just the original crossmember remains, with wishbones, hubs, Avo coilover dampers and geometry all new. At the back, the live axle stays but is properly located with four links and a Panhard rod and sprung, again, by Avo coilovers. Brakes, as you would hope, are hefty discs all round.
Despite a beautifully leather-trimmed interior and lots of Dynamat heat-and-sound insulation, this 238bhp car weighs just 941kg, spread almost equally between the four Dunlop-branded 15in aluminium wheels. These look like a racing Jaguar D-type's, and are shod with 195/65 Yokohama CDrive2 tyres.
As well as its extra urge, the Plus gets tougher brake pads, a plate-type limited-slip diff from Tran-ex (part of Quaife), an upshift light triggered at 7300rpm (500rpm shy of the rev limit) and a lower ride height (by 20mm up front and 15mm at the rear).
This drop is easily reproduced on the regular LE50, because the spring platforms are adjustable, but that's to miss the point. These cars are not just collections of aftermarket enhancements with all the scope for tinkering that implies. One look at the complex electrical system, as laid bare during production, is proof of that.
But could you really consider one of these over a Porsche Cayman?
The first impression as you power away, six-speed gearbox snicking with light, perfect precision, is of the surreal disconnect between the MGB shape you see around you and the very un-MGB sound from the ripping, revving Mazda motor. Next is the strangeness of a proper air-con system cooling you from its home under the original crackle-black steel dashboard.
And then you meet a fast corner on the open, undulating, sweeping road along which you have been pointing the MG's pale metallic green nose. That nose dives into the bend with a precision and a tenacity utterly alien to a B and more like you'd imagine a modern front-engined Lotus to possess, if one existed. The MG balances perfectly as you aim for the apex, then as you squeeze on the power the tail squats slightly and seems both to dig into the road and allow a gentle drift as you straighten the steering and the B catapults out of the bend.
It's friendly and completely intuitive and inspires huge confidence, helped by the high-profile (in both senses) messages from the tyres. Surprisingly, the steering retains the original MGB rack, with the relatively slow gearing needed for a lack of power assistance. The geometry makes it seem higher geared than it is, helped by the optional, and remarkably natural-feeling, electric power steering, which is a column-powering kit by EZ.
All the while the engine blares grittily, its torque feeling stronger than you might expect thanks to the LE50's sub-tonne weight, its power really pouring forth from 5000rpm to the mid-sevens, as recorded on a tachometer that has the original Smiths design but necessarily has more figures squeezed onto its scale. The speedometer is similarly enhanced, reading up to 170mph. In an MGB?