Intercept Plotter aka Craig Computer…value?

Was at a hobby shop closeout sale today, and among the very large inventory of discounted older kits was an interesting grey wooden box. It proved to contain the above-named instrument–somewhat reminiscent in appearance of a training bombsight–which had once belonged to a previous owner of the hobby shop (an ex-RCAF man). The current owner has no idea of the value, nor do I…but I thought someone on this forum might well have an idea. Inside the box the thing’s absolutely mint, and the Air Min blue-covered manual (resembles a larger format “Pilots Notes”) is still present and in very good nick as well. I think the unit is 40s-50s vintage, but that’s really only based on its physical resemblance to the WWII training bombsight I’ve got in my loft, plus the similarity of the manual to period Pilots Notes.

Any ideas, particularly on valuation? I’ll be visiting this closeout again; there are loads of worthwhile, bargain-priced kits on offer…

S.