They *were* straight. I carefully measured and scribed alignment marks. But I bumped the unclamped work a little without knowing it, so they are both off by about the same amount. Not clamping the parts together seems like a stupid thing to do, but my silver soldering jig is just terrible about slipping when up to temp. If I clamp the work down so that it does not shift it dents the metal. I have become fairly adept at brazing without a clamp.
But not today, apparently…
I'll fit is later. I have to take all this apart and reinstall everything and clean it carefully. Right now I am trying to piece together a system of sorts, and once I have all the pieces I can go back and make corrections. I gave up on installing one bit, cleaning it up nicely, then creating the next bit and installing that and cleaning the snot out of it, too. I was getting beautiful parts that were not properly worked out, so all that effort was wasted.
So, for this part of the build, I am hacking, slapping together, bending, adjusting, and writing down everything. AFTER I have this mess "created" and everything works really well, *then* I will make it look pretty, I can also make new parts if I messed something up or decide it needs to be different.
I am assuming that eventually, I will have rebuilt this tuba from the ground up at least twice. It is frustrating, but I seem to be in fairly uncharted waters, here. I have not found a lot of 4+2 tubas with the rotor levers being behind the 1st slide with the valves after the pistons.
That means I am flying outside my normal comfort zone as far as making WAGs with an expensive tuba.
I'm a bit of a slow-witted dullard, but I'll eventually get it. 
