anyone recomend descent leakdown tester?

Swapping your covers to opposite sides should give you what you want.

To inspect seals spring and retainer should come off. This can be done with a two jaw spring compresser and compressed air to hold the valve up. What I do is at TDC rotate crank slightly to lower piston, feed in a clean length of vacum hose, with a tail hanging out for removal, then turn back to squish and hold valves up. Remove retainer and spring and have a look, really not to hard to do and the tool is not too expensive.

Leakdown testers are easy to make, search DIY leakdown tester and you'll find lots.