"Grulla" has been the brand name of guns made by Union Armera for decades, as this 14810 serial shows. The only change I know of (other than various model names) is the stronger emphasis on the "Grulla" brand name and reduced use of the company name "Union Armera" since the mid-'80s.
The year stamp on this one looks like "F1" which is 1960 and which is about right relative to the serial and other Grulla / UAs I've seen. I own one in the serial 279xx series which I bought at the factory 1981, which is marked essentially identically to this (except 1200 proof and later year).
I've never seen a Grulla / UA that wasn't well made, finished and holding up well (in the case of a few I've seen that were "well used").
That said, the M 209 is the 2nd from the lowest grade sidelock I'm aware of (M 208,209, 210, 214, 215, 216, 217, 219 and a Super-premium of various names are grades I've seen or seen pics of). In addition there are named guns like Windsor, Consort, etc. The 209 engraving isn't as heavy coverage, or probably as well executed as higher grades.
