This a Richeville Model 2520 Serial Number 46 Stainless steel with rose gold bezel. The catalogue info about the reference 2520 "Richeville" watch:
"automatic movement calibre GP 3000, 28.800 A/h, case size 32x38mm, water proof 3 ATM, screw-back with 6 screws".
The GP calibre 3000 was introduced in Basel 1994 and is completely done by GP.
Therefore, it may be called an in-house movement (although any contemporary maker makes use of outer sources for springs and screws).
It´s still among the slimmest automatic movements on the market and the base movement for the automatic chronograph movement calibre 3080.
Thank you Peter for all the information.
(this posting was transferred from other section by PeterCDE on 02-01-03)