Hydro Harry,
I believe mine has what is left of a Series II (I bought it with a blown engine, for the tiller and parts). Dad's has a M18 in it, that replaced what I believe was a Series I. (He blew the right cylinder mowing a ditch. We didn't know the angle issues at the time).
I am sure there are other differences. Both of ours have the "Quietline" style hour meter in them, and everything but the engine and rims are red, engine-black, rims-white. I know that when I am looking at listings of x82's, what I listed are the 3 things that I look for clewing me in on IH vs CCC. As for the very early CCC x82's I believe were assembled from the leftover parts from Louisville, so there just about as much IH as the Pre June 81's are.... I think the first big change was the Aluminum Rear....
Also remember this on the x82's....
After the selloff CCC Made:
RED x82's to be sold at the still existing IH AG Dealers (AG selloff did not happen till 85)
YELLOW/WHITE x82's to be sold at Cub Cadet Dealers (That were just "mower" dealers, did not sell FARM tractors.... so there could be Y/W x82 that are exactly like the red ones. Except paint (White hood/sides/dash/rims, Yellow Frame, Black engine/axles) which could explain the red under black.
There are similar changes that I look for on the Quietlines, which help to determine early vs late quietline.
Some of those differences I have seen is:
Early:
Serial Number on axle - same as the wideframes
Rear Tires - have the either "diamond block" or the Z pattern rear - same as the wideframes
Steering wheel - Has the long wide spoke (normally pointing at the seat) with the IH "Tin" insert - same as the wideframes
Hydro Dump Valves - Have the manual dump valves - same as the wideframes
Late:
Serial Number on left side of frame near brake pedal - same as the x82 and later
Rear Tires - "Turf saver" - same as the x82 and later
Steering wheel - 3 equal sized spokes, with the triangular center cap with molded IH in center of cap - same as the x82 and later
Hydro Dump Valves - Have the automatic dump valves - same as the x82 and later
I am sure there are other differences besides these, but these are the easily seen. Mine is a later 1450, built in Dec '77. The wideframe in these pics was built in 72 (has non-braked PTO) and the 782 was in early 80 (Dad has the exact months)