GP did not make any alarm movements those days.
Given the variety of a few hundred makers during 1940´s to 1975, i´m only aware of very few makers to do those (list by memory, so it´s not complete): AS (A. Schild), Vulcain/MST, Jaeger-LeCoultre, Junghans (german), Hanhart (german) and Venus.
GP made use of only two ebauches: Hand wound AS 1475/1930 and AS 1568/1931 (same with date), later the automatic Jaeger-LeCoultre 916. You will find the recent discussion about the JLC ones by clicking here
The AS 1475 debuted in around 1954 and was made until around 1970. The first alarm movement by the well known AS factory which delivered movements to many many makers those days. The AS 1475 is a 11 lignes movement featuring a glucydur compensating balance, flat hair spring, 18.000 A/h beat rate, two barrels (one for the alarm, one for the watch), indirect centre second and 17 jewels. Reportedly a total of 780.000 movements was made.
The AS 1568 is basically the same as AS 1475, but came out in 1956 and does have a date. The reported production total is about 149.000 movements.
The AS 1930/1931 are fast beat ones (21.600 A/h), made from 1970 to 1974.
Ok, so it´s a base movement. But i think these are special anyway: GP never did large production runs like other makers, so the total quantity of GP ones is much lower than other makers. And it´s a GP
Most of the AS based alarm watches did have a fourth hand to adjust the alarm time. The GP ones are a bit different as they do have a window with a disc:
There are GP´s with a center hand to adjust the alarm time as well (i think these are the first ones by GP, the window ones are a bit later).
Besides the window, the watches with AS alarm movements i´ve seen so far are usually a bit more "rough" in finishing while the GP seem to have an improved finishing of the bridges as well.
There are some versions of GP´s calibre 11 / calibre 11.09 alarm movements; earlier make use of a lever:
while later ones do have a regulation similar the one on your picture:
Based on the inscription and the regulation, i would put the movement on your first picture into late 1960´s or early 1970´s.
And a word about the price: GP alarm watches retailed in 1962 for US-$85 (stainless steel) up to US-$250 (solid gold). As far as i know, a Rolex Submariner was around US-$185 those days.
So the GP alarm watch was not the cheapest one, but certainly there have been far more exclusive and more expensive ones. I like them anyway as they are nice to wear and nice to play with. An alarm function is one of only few complications i really make us of.
If you´re interested in the AS base, i could check back the books for some more information.
Hope this helps a bit?
Greetings from germany,