If you take those handles off, sand them, and hit them with a couple coats of teak oil all over, they will look like new and the teak oil is water resistant. Only downside is that the Weber logo will likely be gone.
Or, present day resin ones will fit, but you lose the retro look.
EDIT: Just popped into the Virtual Weber Bullet site, and there was a thread about wood handles. Looks like some in Fort Worth is selling them. Here's a link http://dallas.craigslist.org/ftw/for/943199314.html
My Boys: Joseph (EI); Andrew (EE); Daniel (EE)
My Toys: 10 WSMs (B, C, E, DH, DA, EZ, DZ, EO, DU, DR); 5 - 22.5" Bar-B-Q-Kettles; 2 - 18.5" Bar-B-Q-Kettle; 3 WGAs (EZ, DE, N); 2 SJPs ( DR, DR); 2 Smokey Joes (A, K); Genesis Silver C (DU); Brinkman Cimmaron.
"For when democracy becomes tyranny, those of us with rifles still get to vote"