1953 Admiral C2226Z Restoration

[cluelessgame]

I'm in the process of restoring a 21" 1953 Admiral super cascode model C2226Z (chassis 22A3AZ). I bought it in a local antique store from the original owner for $10.00. and to say it was a train wreck would be an under statement, and, unbeknownst to me, not a good project for beginners. I've re-capped the entire set, and replaced all of the bad tubes, and i'm still getting a dim picture with little contrast. I checked the HV and i'm about 3kv under what's called for, and I don't have a picture tube tester. I'm not sure if the picture tube is original to the set as I found stuffed inside the cabinet the warranty claim card, which has been filled out. The date on the card reads 5/31/55, but the date stamp on the chassis reads Oct 20 1953. This tube is a G.E. 21ZP4B. Also, I'm getting weird, jumbled, extraneous rasters on the top of the picture. Also, on the subject of rasters, they seem to like to double up instead of being evenly spaced, fiddling with the vertical sync helps, they wont stay apart for long. What areas do you all think the problem(s) lie? I've attached photos of what I'm dealing with:
1: pre-restoration power up (I didn't know anything then)
2: screenshot of present working condition: note the dim, low contrast picture with scrambled rasters on top; retrace lines are visible due to brightness cranked all the way up (I've also discovered that turning brightness all the way down dims the picture only slightly, but not blacking out the screen)
3-6: warranty card, enjoy!