oil filter bypass valve disintegration
 

Just finished rebuilding/replacing everything under my '73 (72eng) and went to change oil so I could road test, I've had this car for 2 mo. On removing the old filter the bypass valve endcap and ball fell out of the block. I've yet to find a mechanic, machinist, or book that has heard of this problem, let alone knows how to fix it. FSM is on the way. The valve body appears to be brass and pressed into the block. I'd like to simply plug it off, but have concerns about driving the valve body into the galley behind it if I use a hard plug(freezeplug), and material composition of a soft(rubber) plug surviving in an oil environment.
Many thanks for any help/ideas/references!