Hi Bill,
Three things could cause low compression. Check the ring to see if it is seated,new rings will blowby. It could have a worn ring, but souldn't since it has been renewed. The third is cruves cast in the bore above the transfer ports. These are ment to reduce compression for ease of starting. I filled them on one engine with JB Weld. I havn't run it yet. On another engine they had filled with carbon during use.

Dave