Try searching for "Diana 25".
Sorry, can't help with the value. But in the meantime, here's a little info about it from Tom Gaylord on the Pyramid Air blog. There are links to the previous parts of the blog at the top left of this part.
https://www.pyramydair.com/blog/2012/12/diana-25-air-rifle-part-4/
It is a nice quality little gun about HW 30 power. I can't tell if yours has scope grooves or not but most people want scopes these days, it seems. It should have some little numbers stamped on the receiver right at the stock line. Those #s tell the month and date of manufacture. Yours look to be in decent shape and I would guess value would be about $150 or so.
Bob in WV
This one has a manufacture date of 12 80. It has no dovetail groves and it has the non adjustable trigger.
If anyone is interested shoot me a PM.
the model 25 is a rifle that many variants the last being a 25ds
so there was a 25, 25s and 25ds in the end and all of those were discontinued in 1986
of course the model dates back to the 1925 with model 25a
the last rifle were designed for youths or people of smaller stature most of the modern rifle look similar but have few common parts
525-380 FPS
top value was the 25ds at 150.00 in 100% the 25d 120.00 or what someone will pay
most or all was found the Airgun Blue Book 9th edition









