Column Shift 3 Speed woes

[vintagetin]

I've got a '62 C-10 and the 3 speed trans and column shifter are continuously giving me problems. I've have two other column shift manual transmission vehicles before and they were fine and I commuted in them for years ('69 Rambler, '66 Dodge Charger) and shifted fine all the time but this one is putting up a good fight.

My issues are:
Trans pops out of third while cruising above 45 every 5 miles or so
The linkage at the end of the column slips and falls into 1st gear on it's own when I try to shift into neutral.
Sometimes it won't come out of 1st, and I have to jam the level back down into the 1st position to regrab the gear.
Second gear grinds unless I shift up at 22 mph. I can only down shift to second from third when I drop my speed to about 7 mph. I tried double clutching but it doesn't really help, and sometimes it stay in the first gear.
I have the 235 6, and it has ONE motor mount in the front, and two at the bellhousing. The motor mounts are definitely shot. When I make a u-turn and accelerate the shift lever goes all over the place and I can feel the engine come back down. I cannot find the front mount in any of the truck restoration catalogs. They only show the two mount 235 front set up.

I'm wondering if anyone is experienced with replacing the column shift components, and where I can find the parts and the proper motor mounts. I've never had one of these apart before.

Thank you