Shop Heater to work on my 70.

[lts70]

I found this old heater locally and wanted to see what you guys think. The old guy that I am buying it from has not used it. He said the guy he bought it from had the regulator go out on him and that the fan works and combustion chambers look good. He bought a new regulator (sitting on top of heater in pictures) but was not sure if it is the same as the original as it was removed and could not be found by original owner.

Can anyone tell me if it is worth the $50 he is asking or if the regulator will more than likely work, it is a brand new regulator or do well in my 20 x 20 Garage?

I have been looking for a long time and this is the first one that fits the budjet. Sure would be nice to have a warm place to escape and work on the 70 next winter.