transmission I.D.question

I read a while back that some old international trucks had a t 18 trans in them. This interested me as I have a 1961(i Think) that was given to me when my grandfather passed away. The old truck is trash now from sitting and wasnt much better when he drove it. Anyhow I am finally back home and have verified the transmission to be a very short 4 speed gearbox. I printed all the gearbox identification patterns from Novak and dont see it anywhere. It looks alot like the t18 and t 19 listed, except the shift cover is rectangular with no extrusions. It has 6 bolts one at each corner and one down both sides offset from one another.I dont really want to go thru digging it out to get under it and clean it all up if it is definately not the transmission I seek. It has been setting in a field for quite a few years now with plenty of field animals living under it.just getting under it will take probally 2 hours in itself. Any help would be greatly appreciated. Thanks

 

Any idea where I might be able to find info on transmissions other than novak?

 

Maybe here?
http://www.binderbulletin.org/faq/18.htm#2

 

From 56-69 International used a T-98 4 speed and from 65-73 they used a T-18 4 speed