Nice looking old fan , FarmerAngus .
I'd say that if you gave it a real good going (internal&external) over & a careful 'lube&clean' it would be @ it's best condition & highest value (as a working vintage fan) .
They were & still are , to some degree , designed to be disassembled & maintained , since they're sentenced to a life in the wind & dust .
When doing so , any potential customer/revaluation/etc. would have some incentive if you did a small quickie photo shoot of it's restoration (... well that's provenance 4 the future !) you'd also have the confidence to have/sell/keep a safe-to-operate electrical device , although not so safe around water (ungrounded/unisolated circuits) .
Personally , I really like the look of your little unit & the blades remind me of a sub propeller . Looks like a stout example of the crafts & I'd call it a keeper , if it was in my mitts (esp since I'm fond of like items , in my dottage) !
There's a few folks pretty familiar with lots of pricing for such items kicking around the site , so let's see what others may say !
I surf slow , so checking on Ebay , for me , don't work so quick (for like items & pricing) .
Thanks for posting your item !
