The fattest Tru-Balance I have is 1.50 and the thinnest is 1.32. I have about a dozen in that range and quite a few Brunswick Challengers that are the same.
Something tells me they set the rough turned mark at an inch and a half and then sanded from there.
Most modern house cues are in the 1.20 - 1.30 range and that is what you would probably have after converting a vintage Brunswick house cue.
If your conversion is Oak then I would lay odds that it is a Brunswick.