Well, turns out the diffuser I grabbed was for another style vaportight that they had laying around. I guess karma got me for just taking them lol. I'll hang onto the diffuser as long as it doesn't get in the way (I don't expect it to). I had scrubbed everything down, brought it inside, snapped the latches into the top housing, put the diffuser on one of the housings and: it's 2" longer than the top housing!!! I never thought to see i it was the right fit, assuming they had bought all the fixtures at once and they were all the same size. Apparently not!
So, that being said, I have to order two new diffusers (i decided to keep both vaportight housings and get two diffusers and buy six new latches. I'll keep the housings in the shed and when I get a pair of strips I'll stick them in).
I asked
here for a quote on two diffusers. They repsonded and said they're $19 each plus shipping. Sounds pretty reasonable. I also asked
This place for a quote on two diffusers and six latches. The white plastic latches on the PDF on that page I linked are EXACTLY like the ones on the housings I have and the demensions appear almost identical, so I suspect mine are just an older generation of that housing (maybe not that manufacturer, but I'm sure more than one manufacturer uses the same mold). I also needed to get a pair of plugs for the ends of the fixtures, since the originals were all cracked and broken. fortunately one was intact enough to read the part number, which lead me to
this site, where I explained my situation and asked for four free samples of the part number (since they only sell in 1000 or 5000 packs).
So We'll see. All vaportight fluorescent fixtures are is a fiberglass upper housing and an acrylic diffuser with a strip light mounted inside. The upper housings have two brass threads (one at each end) and the strip light just goes on with two nuts after the fiberglass housing is screwed into the ceiling. You can suspend them with special kits but mine were originally surface mounted and have holes board through the tops where the romex clamps screwed on (they drilled their own holes on top as opposed to using the KOs on the ends, so really they weren't vaportight in their application but they were used in a sheltered location anyways).
I should be able to get the KO covers for the ends and the latches should be cheap enough where I can buy those but I might have to wait on the diffusers. I'll see what the second company gives me for a price on the diffusers and see what's cheaper. $19 each isn't bad but they're 4ft long so I'd imagine shipping is probably just as much and unless they can combine shipping, I'm looking at 80 bucks (20 for one diffuser [times 2] and 20 to ship one diffuser [times 2]) and that's way out of budget for me. If it was free shipping I'd be all over those things. If they can't combine shipping I'll just get one diffuser and buy the second at another time down the road, since I don't need the diffusers in the near future. I've always wanted a vaportight fluorescent though, since I've grown up seeing them at pretty much any camp I've gone to in Boy Scouts (well, major camps where you either stay overnight for a week or day camps and some bigger camps that have mess halls [cafeterias]).