Where did you get that adapter? Switched my Fx Wildcat .25 Compact gauge with a Wika. Have slow air leak do need to use 3x3mm o-ring. This looks like it will seat right on top of the 4mm bushing which I had to pull. In doing so damaged the plastic washer. Have ordered a couple of extra from FX USA. Also ordered the old dustcover which doesn't have the flange the new .25 Compact has. That adapter makes a lot of sense. I noticed the adapter has a plastic seal. What is it called and what size is it? Good job...Easy peasy.
Nick