I really doubt that "cars and engines were considered to belong together then" was ever actually true, except in the production road car sense.
There is an American-developed obsession within the car collecting world that 'matching numbers' are vital, but that appears to be a conviction (one of many) born of relative ignorance, and largely fostered by the grasping motor trade, and one or two largely self-styled arbiters of 'taste'.
Maserati engine and chassis numbers were for many years out of synch, while engine changes were standard practice not only for Grand Prix cars but - admittedly to a much lesser degree - for works-team sports cars. There was in period no obsession with fitting 'the correct' matching-numbered engine into the appropriate chassis before it was sold to a first owner ex-works. If it happened it was much more likely to be simply happenstance.
Ferrari Classiche's almost punitively expensive service has included 'restoring' matching-number engines to host vehicles which have become long-since separated from their original power unit. This was a policy largely adopted by Fiat apparatchiks simply feeding the developing obsessions of the so-called classic or Vintage car dealing trade, and of nitwit one-marque owners' club members.
This notion that a factory-sanctioned engine built brand-new, bearing equally fresh factory-sanctioned number stampings matching the chassis serial, retrieves a state of "genuine-ness" defies both reality, and common sense.
But even the most fundamentalist of classic and Vintage car philosophies just follow the money.
The fine art world is certainly no shining example of archaeological truth and integrity, but the old car world can most decidedly learn many lessons from it where the fine checks and balances of 'fake or fortune' are involved.
DCN
Edited by Doug Nye, 04 October 2022 - 22:29.