UGH... ok stick it back in, power up and first press the far left button which is a degaussing. It "clears" magnetic interference and may help a little. Have you tried pushing each button in front? One should bring up a main CRT menu (not related to the machine) and from there we should have a selection for horizontal position, I hope.
I'm no CRT expert here so I don't know the actual brand but it should be on the back, maybe on the inside part of the frame near the picture tube itself. I'm not sure what that company did, but I live about 8 minutes from there! I doubt they manufactured the CRT. That address is a company called "House of Batteries" and has been there for at least 10 or more years.