I heard from the president of an Amphibious Attack Boat Group – a group of guys who use to be LCVP operators in WWII.
I wrote them some time ago about the LCVP we found in the lake, and asked if they had any info on it. I communicated that our LCVP was identified as PA 52-22.
They indicate the PA52 designation means the LCVP we have was once a part of a ship named Sumter. In doing further research the Sumter carried 36 landing craft all of the PA 52 designation. Ours was Landing Craft # 22 on that ship.