I didn't think they made 924 Turbos in '77, but there was one listed locally over the weekend. I called just to see what's up and didn't get a return call. I don't need another project (said "needs work"), but if anyone else is interested I'll try again. If it turns out to be an uber-rare collector's item, it's mine though.

 

Looks like '79 was the first year for the 931:

http://www.924.org/models/931_overview.htm

 

Could have an aftermarket turbo kit (BAE).