One of the frames the holes are all the way through the frame like they were drilled, the other frame one hole is only through one thickness of the frame, the trans mount where it wraps around the frame, I think I'd have to look at it to be sure, is the outer part and not drilled it acts like a stop for the bar, the other side has a bushing and a E clip to keep the bar from moving over, I'll go look again I maybe wrong. neither one has the front tach a mattic, they had the mule drive that bolted to the frame. I'm not trying to argue with you about this, In fact you are making me second guess myself. Terry you are making me think to hard.
Now I have to go look.

Terry you must be right, and both of mine are add on's intead of going out in the cold I opened up my red binder for 71 tractors and looked, no T-bar listed for any tractor in 71. sorry for douting you , but the one looked so nice just like factory.

MAYBE (I doubt this, but it IS possible) the original frame broke and was replaced with a slightly newer one.
You know there are people out there that would do anything to keep an old Wheel Horse going forever.
My old neighbor has a 1973 14 automatic that now has a frame from a GT-1100 WorkHorse because he thought he was plowing snow with a D-9 CAT and broke the transaxle mounting plate clear off the angle iron!