I don't know, original stye wood spars are still a factor compared to Rainbow and Milman replacement spars and newer ACA era metal spar wings. All of those original wood spars aren't getting younger every year.
If I had to ballpark where I think prices ought to be, I'd start with a wood spar Champion/Bellanca 7ECA with good fabric and an engine below mid time in the mid to high $40k's. A low time engine or new fabric might put it into the mid $50k's but if you have a motivated buyer, anything is possible.
Original wood spar 150hp Bellanca Decathlons seem to top out around $85k no matter how nice they are. 180hp Super D's are dependent on engine time, fabric, interior/panel....I wouldn't even guess what an average price is. A high time engine and original fabric from the early 70's might be a $45k plane, if that? The engine overhaul will push $40k, fabric at a shop is $30k+, prop overhaul, new glass, interior and a couple of modern radios, what's the top of the market with original spars so how much would you spend to do the restoration?