Your resistance measurements of terminals 1, 2, 4, and 5 are consistent with what's written in the manual.
If the green wire going to A4/5 touches terminal A6, then you'll have some issues. I can't tell if this is happening or not, but I'd move those apart a bit and do a little trimming on those socket lugs.
It looks like either you are using lead free solder, or not enough heat (maybe both). When I look at terminals 3U and 3L, I would cook those more until the solder flows smoothly.
The UF4007 diodes that are on the inside of the 6 lug strip (above the power transformer) are not mounted in a manner that's consistent with the instructions. If two leads on two different diodes are touching, and those leads go to different terminals, then you'll blow fuses until your power transformer dies. There's a big warning with red letters on the top of page 38 warning about this exact situation. The body of the second UF4007 diode needs to sit against the lead of the first, and they need to be mounted just like the manual shows.
It's totally possible that none of this solves the issue you're having. Does the fuse blow immediately when you turn on the amp? If so, then I'd be looking for component leads that are touching things they aren't already connected to. If the fuse doesn't blow immediately, voltage measurements will be extremely helpful.
