Ebay does expose your item to a large number of interested people. Sometimes the prices are low for exactly the reason that you mentioned in your note -- the items are not as rare as one would think. On the other hand, I've seen items that are truly rare command final bid prices that are probably higher than what would have been realized at conventional auctions. Overall, it's my impression that eBay has lowered the prices on common items but raised them on rare items. Maybe that's how it should be anyway.
Since you are addressing a group of WW1 aviation fanatics here, you might consider listing the items that you plan to sell and either offer them for sale here or at least announce when they are available on eBay. Please don't
drag it out, however. I don't think anyone is interested in seeing a new post for every item listed.