Hello!
Using rods to reinforce the boiler and to avoid deformation of the the two end plates is a good idea. Personally , I do not install any when I use plates that are 2mm thick and less that 4'' diam.
And you can see that after reaching 10b (=147psi) the end is still flat.
Photo 1
On the last boiler I did , I use 1,5 mm thick on the top end. And I had a deformation when reaching 6 b(=90psi) pressure. So I ended up with my steam valve, whistle valve and safety valve bending like the Pisa tower. It took me some sweats to straighten them , and still , it is not perfect.
Photo 2.
Finally, I installed the CATON inside teh BAT.
All is in place and I should be able to steam her up in the coming days.
My only problem left is to be able to get the steam out without going along the chemney = too many elbows. But I may end up to do so. My first intention is to let the steam escaping through the "Tea pot" ! Not sure that I like it !
A few pics to get your recommendations.