^ bro
1k is 1000 ... i belive u trying to ask that meter fully completed 100k ( 1 lak ) and now again back to 12k reading around ....
well the front screws of meter ( from Dash inside interior ) might tell the story if the screw driver touched them, otherwise if its done clean, then no chance of getting it, better look at interior and engine bay, if they are way clean just like brand new, then assume it runned genuine on meter, rest dont worry if there isn't any prob with it.
i owned previously a margalla late 94, sold for 370k about a year back, ( Regret every moment y i sold it ), it was runned 320k but on clock its only 20k, this all long milleage is with stock engine, rings, everything, not even one bolt of engine opened, just few times for tappet adjustments, thats all ! and still it gives till now 200+ km millage on 55liter cylinder on long routes, also chilled Ac with no prob at all, my frnd bought it from me and still there is zero problem .....
My personal experience, there nothing happend to petrol cars around 400k millage if driven carefully .....
Enjoy ur ride .... Gud Luck