Check those again, especially the one that is parallel across the focus potentiometer. You need to check it twice, once with the focus pot turned all the way clockwise, then again when it all the way counterclockwise. You should get a bit less than 510K one way and something very low the other. Does your small window of in-focus happen to be near one end of the range? Also, make sure you check the small 180K resistor in that chain as well and if one is bad, replace them all with Vishay HV metal film resistors, HVR25/HVR37 series.
I just checked with the pot in both positions you mentioned and all of them read 1M just like they say in the service manual. The smaller one says 200K in the service manual and reads 200K in both pot positions. David Hess mentioned that the resistor issue was fixed in 2225.
it looks like you have WAY too much intensity from the picture. It would be hard to maintain focus at that brightness level. How does the focus act with the beam at lower brightness? There may be other problems like the beam blanking or beam limiter / CRT bias being somewhat off. As the other posters mentioned, this series of Tek scopes was plagued with CRT focus and brilliance resistor problems as they aged. I know of two 2213's that got trashed because of the factory screwup that put too much voltage on the C.R.T. filament. The cause of the early C.R.T. death wasn't known by the company I worked for that owned the scopes and they chose not to repair them and decided Tek quality was no longer worth the insane purchase price or factory repair price. Tek in the 60's and 70's were bulletproof. Then they started 'costing out' and their reliability went to crap. Because they had so many in house built hybrid modules and I.C.'s and made them unavailable for do-it-yourself repairs, as well as obsoleting all parts within a short timeframe other players in the oscilloscope game were able to gain traction. Tek really got laughed at when they were selling portable battery scopes (212 etc) with 500khz bandwidths and the 5110 / D10 series with 2mhz bandwidth for multiple thousands of dollars. I still own a lot of Tek stuff but can't afford and won't buy any of their newer stuff. I have Tek scopes here at work with probes costing over $3000 each. They get boogered up easily and cost over $2000 to repair if they can even be repaired.
My camera makes it look like I am using more intensity then I actually am, however I turned down the intensity and had a little more success finding the focus, but the same problem persists. The focus issue is in the middle of the range. This makes me think it is the pot because you can eventually get to the focus in the middle, it is just hard to find because there is such a small area where it actually focuses.
I will probably move forward with replacing the pot since djsb and jdragoset seem to have success with this. I couldn't find the pot on sphere research in Canada. I just emailed them to see if they might have it. I found this replacement on ebay:
https://www.ebay.com/itm/124679162494?hash=item1d07750a7e:g:VyoAAOSwQ3Zgdbpv however it is not the exact part and needs to be modified as described in the eBay description.
jdragoset if you can send those pictures of your replacement ideas that would be great.
Sorry for the late reply everybody I've been putting off this project for awhile. Thanks for all of the great suggestions!