Review this thread, contained in the posts you will find several links that take you resources for determining what the ihc "model" and "code" numbers represent:
While I realize the vehicle discussed in that thread is not the same is yours, the process is exactly the same for all motor vehicles produced by ihc post-wwii. None of the documents referenced in that thread contain complete information, I use both of 'em together to reach a conclusion about any one particular IH code. And...there are big holes in those docs also, they are a guide for research and not the last word in accuracy.
In reading through your lineset, I'd say that rig was originally a very well spec'd 4x4 t'ette! Typical of what we see alot of up here in timber country as those were the primary timber crew vehicle in the 60's and 70's in the northwest. The pto/winch combo is a really nice touch, as is the 4.09 gearing.
Attached here is the front of a sales flyer for a c1200, this shows what the original option selections would have been that dealer would have picked from to spec your particular for production scheduling