Jerry,
To order a book please email me:
m.baudino@libero.it
I have a few spare copies.
RG means Renato Gamba. Mr Gamba was the Italian importer of Mauser Parabellum in the '70. He made also the HSc model using a Mauser Patent.
When the Mauser Parabellum came back, he made a special order for Italy. He was not able to buy all the pistols he ordered. Therefore these unsold pistols were sold mainly on the USA market.
Ciao
Mauro