There's probably a lot more places to go to get tank parts, but here's a couple places I've used. Bungking is great for mounting bungs and all sorts of cool stuff. I have a lathe and it's not worth my time to make all my own bungs, it just takes too long. Outlaw Iron Customs makes some cool simple domed gas caps with a trick little vent/filter system so you don't ruin your paint job. The come in either aluminum or brass with a mild steel filler neck. Anyone have any other places to check out for parts, leave a comment so I can peep it.