Welcome to the forum! Post up some pics, tell us all about yourself over in the 'Welcome Wagon' section, and stay a while! We're a fun group....... Marshall
the short answer is whatever someone will pay for it! What you should really do is check out valuation guides like Hagerty and NADA and see if you can find any similar wagons for listed for sale. Pricing guides tend to be based on condition and will outline what each condition category means, so pay attention to that. You've not really given much detail on the car here, so no one will really be able to say. I've found the pricing guides tend to be a bit "inflated", but take a look and keep your expectations reasonable. You can also try listing the car for sale at whatever price you think, and you'll know from the level of interest if you're too high or too low. Start with the price guides. If you want some advice here, best to post a few pictures of the car, including interior and engine bay so we know what you've got... we do love pics here!
I agree with everything dmfconsult said. Looking forward to seeing some photos of this one. Welcome aboard.