Autokraft Mk. IV competition version?

I was thinking that the Mk.IV only came to the US with a 5.0 liter Mustang engine but then saw one at a concours in Long Beach fitted out like a Comp 427 with side pipes, wider rear arches, and what someone said was a 351-C.
Then I heard that some German fans ordered them with no engine and put in 427 engines. So what I want to know is, was it possible during the heyday of that car to order it with anything other than a 5.0 in the U.S.?

Also I thought Richard Buxbaum was the importer but heard later Muck Motors was. Was Buxbaum out soon in the car's history in the U.S.?

Finally it one wanted to make one of these into a lookalike for a 427 S/C
what would you have to change besides:

-wheels to knockoffs
-rear fender arches
-side pipes through body
-dashboard
=gas filler cap

Has it been done by anyone? I like the fact that the Autokraft is documentable as a regular production car and not a kit but I feel it looks
weak compared to a 427 S/Cand would want to change it to a 427 S/C clone if I had one.