There are posts on here about the draft control. It is supposed to automatically raise the 3PT when plowing, etc. to keep the depth the same. The harder the pull, the less is in the ground. ... kinda.
which.. by your own description is NOT keeping the depth the same. it's keeping hte draft or pull the same .. or at the threshold you set it anyway, thus deptth changes as soil composition changes.
To the OP..
your pto is non live, step on the clutch to shift gears and engage / disengage pto.
do yourself a favor and get the owners manual and a shop manual.. even if it is only the thin I&T FO-19 aftermarket service manual
DO read the owners manual. also.. buy a master parts catalog. you will be into less than 60$ for all 3.. and you really should have them.
as mentioned.. pto cover screws off. a strap wrench might help ya or a pipe wrench.. usually they come off pretty easilly.. especially since 1950's era pto seals usually weep a lil.
also.. if oem, the shaft will be 1 1/8 6 spline. Yer new machien will want 1 3/8 6 spline.
ya got a few options.
1, replace pto shaft assy. it's about a 110$ part, slides in and out with 4 bolts removed.. though do be carefull in and out as it passes thru a seal that you don't want to damage the lip to when removing or re-stabbing.
2 or, if the bearng and seal are good, you can get a sheetmetal bushing to make up the diameter.... it's the worst of the ideas and i DO NOT reccomend it.
3, get a stub adapter.. it will slip on the oem small stub, and pin on with a roll pin, and then it will look EXACTLY like a modern 1 3/8 shaft end complete with another hole for pin on implements, and the groove for quick latch type fittings. this is a good 4$ option.
4, get an ORC ( orver running clutch ) made for your spline end, and to the implement spline end.. they make em, 1 1/8 to 1 1/8 or 1/8 to 1 3/8
or 1 3/8 to 1 3/8 I bet if you look, they make a 1 3/8 to 1 1/8
that option 4 is one of the best.. especially with a non live pto. keep inmind you may have to adjust / shortent he driveline when you add an ORC.
soundguy