Vacuum and compression both sound low to me. Rings may not be seated yet but I would still expect higher numbers.
If you squirt
oil in the cylinders, the rings will seal. So you can check compression then squirt a couple pumps of
oil in and recheck. If compression comes up, then you know it is the rings leaking.
Also a compression leak down test will show if there is leakage, but not where. If you use the
oil trick and the compression still leaks off then the problem is most likely valves.
Hope that helps you narrow the search.