Ed is correct, however some clarification:
The J&S trucks currently under refurbishment were built for B&SR combine 11. Edaville move them to SR&RL coach 21 (F&M 2- currently owned by ML&M and at the WW&F). Thus we will reunite the trucks with F&M 2 on a reversible basis (in other words the coach still belongs to ML&M and the trucks belong to us).
The B&SR swing mo trucks from coach 2 to box 56 are a temporary measure (a few years) to buy time to construct a new set of freight trucks. The new freight trucks will be WW&F common bolster trucks destined for flat 126 (a WW&F repro). The trucks currently under 126 are B&SR swing mo trucks, which will get moderately refurbished and placed under box 56. This frees the good trucks that would have been under box 56 to serve as operating alternate trucks, allowing systematic refurbishment of other B&SR swing mo trucks in passenger service.
A couple ancillary goals: the truck work is connected to our implementation of the vacuum train brake system, as we plan to install vacuum brake cylinders and reservoirs direct to trucks. This will make fleet wide implementation much more practical. Further- box 56 leaving shop bay 3 will permit the boilers for 10 and 11 to move into that space. The boiler work really deserves dedicated workable shop space to spread out and properly tackle the many parts of the boiler project. (L10 itself will go in the enginehouse, where it will receive some non-boiler improvements).
We’re still looking for an opportunity to change that up a little- and get some other trucks under 56, so the good swing mo’s out of coach 2 can help with vacuum brake implementation right away. However, short of an alternate set of trucks for 56, we’ll stick with the plan above, get 56 in service and free shop bay 3 for boilers. (No, neither MNG, ML&M, nor SRRR have spare trucks- we’ve asked).
We’ve weaved a tangled (but hopefully logical) web of trucks

Thanks
Jason