None of the above. At the third time of trying, I obtained 1/8" BSPT valves which fit. The pair of displacers I ordered arrived today. I decided to buy one of each to have a pair ready to swap in and then take the pair removed, modify them and fit those so I was less time pressured should the weather turn either good or bad. Which would be fine were they not both rear ones. So I'm in a quandary. Rear ones appear to be more failure prone so I suppose that is a good thing but it does mess my plans up. The front ones are at least supposed to be easier to remove so I suppose I can still do a side at a time but I regas at work so I'm off the road for a bit longer than I'd like. Still, looking on the bright side, both the lower diaphragms are dry. I haven't drilled the tops yet; The units supplied were by no means as good as those pictured so I might still have a duff pair...