Mgreen, "estimated figure on what it cost to restore a panel wagon" starts out merely being like a weather forecast. It depends on many things. While I've noticed over the years not many people are willing to "discuss" money I'll share a little of my experience restoring a 52 1/2 ton panel which, by the way was so bad it should have been crushed.
After 6 years and a complete frame off resto I had put a little more than $18,000 into the panel in 2005 to 2012 money. Except for the paint, and most body work I did all the work myself in my shop. This was also using an engine I had only 300 bucks in it, an 400 in a 700R4 transmission. Included new floor pans, cowlings, running boards and hunting down parts in a U-Pull-it yard. Everything new, or rebuilt.
I think you get the picture. Sounds like your panel is in much much beter shape than mine was but I do suggest doing some homework and writing down expenses expected. If your not dedicated to spending what it will take then don't start until you are. For most follks doing a "complete" restor I tell them if they don't have about 20 grand to start a major job don't start it and have a pile of parts to look at every time you come home from work.
Hope this helps in some way. I drove my panel for 7 years after resto and enjoyed every minute of it. Drove it on many long trips. Only sold it to thin the herd down.
