It's a crapshoot. It probably has a tube which is compatible with the CR23 adapter...or, perhaps on another run of the same TV they used a tube which has a CR31, instead.
Is the TV free? Then just get it. If they're asking big bucks for it, forget that TV altogether. Ask on Craigslist for anyone that has a 19" TV. A lot of people have replaced their tube TVs with flatscreens, and are keeping the old one, either because of the recycling cost, or "just in case".