Thanks, Guys...
The gun is not P-xx stamped anywhere...neither is it import stamped (with USA importer stamps).
I forgot to take photos of the front of the trigger guard and barrel underside...to show serial numbers and witness marks (there is one clean strike across the barrel shoulder and the receiver...). I will take a few more photos this weekend and post...serial number really is "555"...with lots of "55" on the correct parts.
Regards,
Pete...