Has it a matching engine number, who gives a rats

Just noticed a Triumph bobber advertised on Evil Bay it’s listed as a matching frame/engine bike, thats ridiculous as it has a late front end and a hard tail frame bolted on, what does that mean more or less on the value? Irrelevant I would think, I remember going through the Triumph works in 1979 and there were two assembly lines, one with engines the other with frames, the Brits never stamped the frame number on till the engine went in as purchase tax had to be paid on a complete machine. Anyway where to two lines met a huge Brummie ( that’s a Birmingham native) physically lifted the engine into a random frame! These days folklore has it that each engine was hand made for each bike and they were all hand lapped to fit, “bollocks” 75% of bikes made before the seventies Indians included have had the engine or frame changed, how do you think motorcycle wreckers survived, people had no qualms swapping a engine over if it was worn or blown-up and if it was a later version more the better. It wasn’t till the late seventies that owners and buyers became anal and that’s not for the better I hope one day people will realize the stupidity of this fad and people buy bikes on their merit.