Europe had the W124 prior to '86 when offered here in the US. That is simply a W124 Euro 300D. Quite a rare bird!
No, you can't just slap a turbo on a non-turbo car. The list of extra parts is huge and the engine is made different internally from one designed for a turbo.
I would expect the $910 current price to climb prior to auction end......

__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John