I might buy a Frankenbenz if:

1. The work was done well and there was appropriate documentation to go with it so I could still easily figure out which repair parts to get when needed.

2. It's something I like. For example, I'd pass on an N/A motor in a previously turboed car. I'd also pass on any manual to auto tranny swap, but I'd be heavily interested in the reverse. I'd really get excited about a manual-everything 240D with the turbo 617 swapped in. I actually saw a 114 250C with a 350 Chevy engine on Craigslist last night, and after the issues I've had with my M130, this sounded like a good idea to me.

In the interest of full disclosure, when I was 17 I did buy an engineless '63 Dodge Dart that had been a Slant Six and install a 360 out of a '79 Chrysler Cordoba. It was a hack job, but I had fun with it.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.