The old saying applies: "The worth of a thing, is what the thing will bring." In other words, I don't think that there's any sort of established price for such a device, as there are far too few bought & sold. Even finding someone who wants it would not necessarily be easy. Most of us who have such old-timers around do so because we LIKE them, certainly not for investment purposes, or even as something to buy, sell, or collect in quantity. I suppose that there might be a sort of "working museum" somewhere that could use such a compressor, but most such places are intended to replicate life in an earlier time than this would suit. A modern compressor of similar capacity is probably cheaper and easier to maintain [and likely to be sold with an instruction manual containing information about suitable lubricants, service intervals, and so forth], limiting its appeal for actual workshop duty.
That said, it would be sad to see such a thing relegated to the scrapheap; it is in some respects a piece of history, and as such, ought to be treated with the dignity befitting its age. This forum isn't concerned with pricing or appraisals - but anyone subscribed can chime in with his / her opinion of what he / she would give to have it. Cost of shipping is likely to make it cost-prohibitive for anyone not relatively local to you, and having access to suitable transportation. If you're trying to sell it, it should be in the part of the forum dealing with such, not here.
BTW, we're always interested in pictures, and anyone interested in old tools will likely find someone with similar interests around here. If that's where you're coming from, why not join up?
