p&h omega crane – help with parts..

so i finally got my hands on a conrad p&h omega crane. i found it on ebay, it's kind of dusty and beat-up, but will serve it's purpose. i was wondering if you guys could help me out with finding spare parts, interchangeable parts, etc. b/c this thing needs some work. this is the link to the listing: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWNX:IT&item=390016802179 of the four wheels, one of the wheels are broken (just hangs there), one of them are glued with what looks like elmer's glue (won't rotate), and one of them is really loose. (fourth one is okay) i'd like to replace them, but it doesn't seem like they're 'fixable' (ie can't take it apart).. any insight? i also definitely need to replace that tacky green knob thing (sorry i don't know the terminology) and get some wires, hooks, etc. any help is appreciated