The etches for inside motion are included in the LSWR/SR kits, which allows construction of a non-working, ‘dummy’ inside motion. Additional kits are available to convert these to working inside motion. They include lost wax axle cranks, turned brass eccentrics, rivets and detailing parts and instructions in order to assemble fully working inside motion. For those who have an earlier kit without the etches, the full inside motion kit is still available.
| Ref | Locomotive | Price for full kit | Working parts only | |
| IM 19 | T9 4-4-0 | £20 | £12 | Download instructions |
| IM 22 | Adams Radial 4-4-2T | £20 | £12 | Download instructions |
| IM 24 | Adams T3 4-4-0 | £20 | £12 | Download instructions |
| IM 26 | Drummond L11 4-4-0 | £20 | £12 | Download instructions |