A fair enough point but remember back in the late 90's these cars were worth less then than they are now,I had a mint moonstone with leather,fsh,chipped etc back then and couldn't shift it for £4000,ended up selling the good bits then letting it go to a breaker for £2500 which got me my money back.
A car like that would in theory be double that now say £8/9000 but book then wouldn't have even been £5/6k on it.
The cars passed 15 mots since then so my guess is if it was hit hard it's been repaired well as it would be rusted into the ground now if the repair were poor.
Remember in 1996 there was no VIC system and realistically if your car was written off it was entirely up to the buyer to investigate rather than a marked logbook of any kind,the cat c could even be a clerical error or even a later category from vosa/dvla post the new rules.

A mate of mine had a cat c mr2 back in the late 90's,pre VIC and the car is still doing the rounds with the owner oblivious to the fact,it was stolen recovered on the key,some loons drove it round the block,shit themselves and ran away,no actual damage just the owner didn't want the car back afterwards and that got cat c!!!!

Don't read into it too much guys,there's loads of reshelled/rung/totalled cossies out there with clean books that people drool over not half as tidy as this one or as honest but out of site out of mind eh?