GX-E-CS3 / CS3-I Rings Replacement
It was OK not complete though, No seals for connecting the high pressure lines.
I have three GX compressors, a CX3 and two CX2's and all work as expected. These are well engineered, we'll made compressors. I've used my CX3 every day for around two months and not a single hiccup. It fills my 480cc Brocock from 150 bar to 250 bar in 5 minutes and doesn't get much past warm.
If you're looking for a compressor they can't be beat and parts are readily available.