They look good, may well be worth the effort. Another little trick, maybe put 6V on the fan motor to get a bit more velocity out of it.
eBay: 265148405879
2 Pieces Air Pumps Diaphragm 3V 6V 3.7v DC Small Mini Miniature B2, $12.08 & free shipping from US seller.
I have a couple of bigger versions, I used one to enhance the Lionel #394 Beacon by blowing a little air up through the rotating hood.