What do I look for in used records?

I've been absent from vinyl for years. Actually, unless I resort to my 25 year old Pioneer SX-850 and Technics SL-1400, I'm still absent. But after reading some of the posts here, I dropped in the local Goodwill to see what might be found, and picked up a 1955 copy of Brahms Violin Concerto - Heifetz/Reiner RCA Victor Red Seal LM-1903.

I'll admit, I don't really know what I'm getting with this. I'm not even sure this is stereo, since the label just states: A "New Orthophonic" High Fidelity Recording.

Is this good? There were several others that I could have also grabbed, but thought I'd ask here what to look for before proceeding. thanks