K2CNC bearing block repair/replace

I have an early K2CNC 24 x 36 system. I think its nearly 20yrs old, came as a frame where I added the motors/electronics etc. I use it regularly, but not continuously like a commercial shop might.

One of the linear bearings that supports the gantry now has about 20mils of play in it and its causing chatter in the Z axis, especially when I'm at that end of the gantry AND using a down cut bit. So its time to get that fixed.

There are 6 linear bearing in my system, 4 that support the gantry and 2 that support the Z axis. I rolled 1 of them down the rail to get info on it. Unfortunately, the manufacturer is not marked, but the series is formed in the end cap.

The series is HBW 20TA, The rails are 20mm wide x 21mm tall. I attached a picture of the rail cross section. I haven't seen a cross-section like this in the catalogs I've searched. On 1 thread, it said that K2 used THK bearings, but they don't list this model nor have this rail cross-section.

I did a google search on these and didn't find a match, I found a Milwaukee part and possibly a Hiwin part, but no details. A search of the HiWin didn't turn anything up that matched..

Has anybody repaired or replaced one of these bearings? Have a good lead where I can hunt one of these down?

I'd like to find a replacement bearing, pull this one off, put the new one on and only be down for a few hours. I haven't removed the bearing from the rail since the machine is still working and I figure once I do, it won't work again until this is resolved. Because of that, I don't even know what the bearing guts looks like. The end caps appear to be intact however.

I'm guessing if these are out of manufacture, I could pull the unit, finds some new ball bearings and rebuild it?
Any assistance appreciated !