#7 suffered from severe pitting in the front course of the boiler back about 1971. Back then the only way to repair pits in the boiler was to either install a riveted patch on the exterior of the boiler or replace the entire course of the boiler. Cass' decision was to have a new boiler course installed. As the first course is also the tapered course of the boiler, it was a somewhat complicated piece of steel to have rolled and formed. The first one didn't fit (missed by several inches), a second one also was messed up somewhere.
At this point the State threw up its arms and gave up. They already had Shays 4, 5, Heisler 6, #3 was rented from OR, Pacific Coast #2 would be there shortly, then WM # 6 showed up in 1980. So, #7 wasn't really needed. It was too bad it happened then. With the old boiler regs, you had no choice but to patch or replace. Now, regulations allow pits to be welded up with the boiler in place.
Since then, #7 has suffered from being too close to the shop. She has lost a lot of part to other engines.