What about simply finding an aftermarket air filter? I remember that the air filter for my EX-NH 1920 was 35+$ from NH.. and like 18$ from Napa.
Only problem is that napa couldn't cross over the CNH part number.
I found a good trick. Hit a filter site that does competitor cross reference, get your number crossed to their filter.. then either use that filter.. or let napa try to cross that new filter. For examply. My CNH part number crossed over to a fram filter number from
www.fram.com.. then NAPA crossed that fram number over fine.. even though they couldn't cross the CNH number.
There are other places.. like Carquest that can cross numbers as well as many of the big filter manufacturers websites.
Lastly.. places like filtermart will cross virtually any filter number over to ther own.. but then you are buying from them online.. still probably cheaper than a 81$ CC fitler.. etc.
Try crossing yuor number at fram / napa / carquest and see what you come up with. Post the price back.
The probelm I see about swapping the air intake housings is you want the same filter density, amount of media, and air flow characteristics as the oem filter.. You may or may not duplicate this using the flat filters... At least a crossed over number is similar application.. etc.
Soundguy