Sorry about being tardy on your approval. I must have been asleep at the switch.
thats a nice Mil.l.
SB tended to use proprietary pulleys. You may need to make your own. I rebuilt a SB Drill press some years ago and converted it to a multi speed unit with an extra step pulley in the middle.
This was a SB option.
I made my center pulley.
It took a few days but worked out in the end.
SB tended to use standard bearings. The noisy ones can be replaced. I would first try a very light lubricant such as Kroil and see if it quiets. Often the old grease has solidified and a BIT of light oil will soften it up.
Not sure if there's a separate group for mills or not, didn't see one. I have a MIL 3212 mill bought at a university auction that is missing the correct motor pulley. They installed a single sheave, possibly to run off a vfd. I'm looking to replace it and got info on another group that is a little bigger than a 3-4-5-6 pulley. 1" motor shaft on mine.
The idler shaft bearings are a little noisy but it runs fine on my simple homebuilt rotary converter. Need to get some Velocite for the quill instead of the 3in1 I've been using.
I got some generic drill chucks with the nmtb30 taper, had to mill notches for locking screws. This was the first job I used it for, actually. Tilted the head way over about 48 degrees to match the few tool holders that came with it and laid the new holder flat in Kurt vise ($60 at estate sale! ). Worked great. Where do you get to holders?