Been following along and also read some of your “leakdown” posts. I’m doing much the same work to my bike (see my “Early Sandcast found” project posts. I always start by getting my project bike running. That usually tells me what needs doing. My engine definitely had the pucks leaking, so I’m digging in, just like you. I also have some bent and cracked cooling fins on the barrel section, so needed to pull the top end apart, to get that part vapour blasted and repaired. While it’s on the bench, I’m going to give it a light hone, new rings, gaskets, “0” rings and seals. The valves are out of the head and just need a light clean, lapping and re assembly. None of this was really necessary, but I have lots of time and this bike is worth some extra effort.......
Looking at your engine photos, the base gasket and head gasket look tight. If I were you, I’d pull the cam, rocker gear and cam pedestals. You need new new pucks and “0” rings under there for sure. When the top of the head is bare, retorque the head. Put number 1 and 4 cylinders at TDC. Now check the leak down on those two cylinders. If you hear leaking at the intake or exhaust valve, drop the piston down the bore 1/2 way and strike the valve head sharply a few time, with a soft hammer. Make it pop open and shut, with the air pressure on. This will clear any crud from under the valve sea and give you a much more accurate reading. I assume your engine has not run for a while? Your rings are bone dry, so you might be wise to spray some WD40 in there and rotate a few times first.....
If you get reasonable readings across the 4 cylinders this way, just leave it alone.....