Lets build a camelback,, or two.

[e-paw]

I marked out the rear row of rivets the same way as the front. the only difference is that it is actually 2 rows of staggered rivets. Most of the brass past this group of rivets will be soldered inside of the boiler tube.    

I cut this in half to make the 2 sections that I need for both engines.    
They were then rolled up and placed inside the boiler tubes to rest & conform to a rounded shape, this will make it easier to solder them up tomorrow.