I got the thing back together and bolted to the stand, I got it running and found out why the bottom bracket rusted so bad. There is a slight leak, more like a seepage on one of the lower fittings. It was probably leaking for years. So of course I had to un bolt the thing, dis connect the 7 hoses, take it to my workshop and fix the leak.
Now I am waiting for the sealer to dry. I think I will test it before I put it back on the tank like I should have done in the first place.
The good news is that the new venturi valve works better than the old one but more bad news is that one of my MH lights that I did not touch, does not go on. So I have another "fun" thing to fix