That is actually a TM-UM horizontal mill with a factory vertical head I believe. This is what a Hardinge TM-UM horizontal mill looks like in it's real, normal life. I paid $700 for it a couple of years ago and felt it was a fair price. Check with the seller as to the whereabouts of the overarm, arbor support and arbor. He may have them in the back of a cabinet somewhere and forgot about them.
I suppose it is called a "Universal" because it can be either horizontal or vertical. I am far away from this machine so I am not able to put eyeballs on it. I will ask if they have additional parts for it.
Thanks to all for the help.
That looks like a model C head. Bridgeport offered some simple heads early on that could be used on other machines. Those little heads had a 1/2" collet maximum capacity,I think. The M head did. The M head is more complex,with a movable spindle. I have a rare high speed M head that will go 12,000 RPM.
What those Hardinge mills are worth probably depends upon where they are found. Around here,they sell usually for about $1200.00. Up in the North East,in the industrial states,possibly less. They are nice little mills,very well made,but with limited table travel. Probably good stable mates for a lathe like a South Bend 9" or 10".