Coming late to the party but to make sense of any pre-merger AMG is impossible.
Remember AMG was a tuner at the time prior to it's initial co-operation agreement with Mercedes in 1991-1992.
AMG had franchised dealers/installers as part of their global network.
These dealers procured parts from AMG Germany for installation on customer cars.
Some of the shops had extensive capabilities such as AMG Westmont Illinois in the USA.
They went far beyond in some instances what AMG Germany offered.
Everything from trendy 80's gold emblem packages to custom sheetmetal work such as the ducktail on the 124.
Hammer builds were typical done on the lowest spec cars, including a diesel import from Canada on an estate.
The AMG badge was offered to any client who had three mods done by the dealer...anything from pure cosmetic to performance.
As far as the widebody C124 from my research it is one of the rarest pre-merger AMG builds...only a handful were built pre-facelift with a few more done post facelift by AMG Japan.
If you were to carefully inspect any AMG dealer or even AMG German sheet metal/body panel work you will see that it was not done to the highest specification.
Everything from overlapping weld joints to variance of over an inch side to side.
Crude because delivery time to the customer and maximizing profit was first and foremost.
Builds of pre-merger cars turn up frequently and some have been until this time unknown..
The key is that AMG and its dealer network were tuners and all work was ala carte to the customers spec..hence my comment over the years.. " Pre-merger AMG's are like snowflakes, no two are alike ! "
The best site for pre-merger knowledge is linked below:
Mercedes AMG Classics ? Index page
Ed A.