What I see there is the strong possibility to take any model bay window caboose model produced in the last 30 years…..
Even a cast-off old shell…
And rebuild it to become that wanted caboose.
Splice and assemble two bodies into the single needed body if you wish.
The old body or full car is the bulk of the wanted ‘kit’. The majority of the rest of the ‘kit’ is common assorted sheet styrene or similar flat material.
It’s even more fun than just assembling a normal kit.
Best to ya,