Perfection is no leak at all, but where do you draw the line, maybe the crank is in such a place where a little wear will allow a minute leak while stationary but seal whilst in motion.
If there are no leaks around the reeds and carb boot or any in the crakcase joins, the leak could be in the tester itself, it has been known that a pressure gauge to leak internally.
Providing the idle can be adjusted within specs, and a plug chop proves satisfactory, then go for it.
Re test for leaks soon or if there is any doubt that there is a problem.
This is a situation where us oldies have the advantage over you young uns, we can often call on our experience to call it a go, or a no go.