Anybody know what calibers and barrel lengths they were made in?????

here is a rarity chart for the Ruger #1's. not sure how accurate the numbers are, but it's a start.

http://classicsportingarms.com/?page_id=10

I had a .270 AB at one time. Have also seen the 204 Ruger

I owned serial #800 in .308 Win, but the rifle wouldn't shoot worth a shit, so off it went.

I miss it now of course...

The AB is a little bit of an oddball. It has been cataloged in 204 but for the most part it’s a special order rifle as far as i know.