Thanks for all the replies. This is sort of a special situation, it's a part of my family's "collection" and I'm trying to figure a fair price for my friend. It's tough because it's a rare car, but has rust and isn't a desirable year.
it's true that it's a rare car. but rare doesn't always equate to desirable nor valuable.
and here's the part where i'm gonna squeeze your shoes: without the original motor and transmission, it's just a pile of rusty parts.
the value of something unique like this comes from having all the pieces, and this is missing ostensibly two of the biggest. add in the rust issues as well as a missing interior and the overall monetary value is dog water.