nissan guy,
While I can't say if it'd be worth it to you to restore your RS III's; I do know if I owned a pair, it would be worth it to me to keep them running. Those speakers are definitely worth the cost and effort to restore.
If you need to be cost conscious in the restoration, just find 1 replacement woofer to start, and swap out the one odd upper woofer. Since the upper and lower woofers cross over at different frequencies, it would work better to at least match the upper midbass-woofers 1st, then as funds permit, buy more woofers as they become available, and replace both lower bass woofers at the same time, to complete the process of bringing the drivers back to stock.
As to availability, that's a fairly common Infinity woofer:
http://www.infinity-classics.de/infinity/technik/manuals/RS_III_technical_sheet.pdf
8" WOOFER
#902-4976
Substitute #902-5030
It's also used in the RS-4B, RS-6B, RS-7B, RS-8, and the RSe (if not more). So, look for those model drivers. I don't think the older Qa and Qb drivers would work as well. But, you never know.
Also, there's a current auction (not mine), for a set of 4 RS-4B woofers, that are compatible with your RS III's.
Heck, Infinity even still lists a current version of that 8" woofer as still being available from Infinity Parts & Accessories:
http://www.harmanaudio.com/search_browse/partlist.asp?Parts=CS940404&BrandId=INF&MarketId=HOM
So, give it a try. And if you change your mind, let me know. Maybe I'll take 'em off your hands!
Good Luck!
They actually need 3 woofers to be brought back to original. Are the woofers hard to source? Are they expensive? I seem to find lots of qa,qb speakers avialable on ebay, would any of those be suitable replacements?
They are pretty cheap, but if i have to put alot of money into them i dont know if it will be worth it in terms of sound quality per dollar. Someone correct me if i am wrong.