you have a rarer case and also have the plug. It's the case and plug that will add to the collectable value - if you sell to a collector.
right now ones like this are selling on Ebay in the $50- $100 mark (higher if serviced or has lots of accessories), though there listing with asking up to $250. Figure on Craigslist to get half what they sell for on eBay - but one never knows who might be looking.
I paid $50 for mine at an antique mall, then another $15 on ebay to get the plug (along with some other stuff that I didn't need).