Disassembly of a K-Line Woodside Caboose

[palallin]

I am looking to paint a K-Line woodside caboose and letter it for the MoPac.  The problem is, I can't figure out how to get the thing apart.

I have removed the top of the smokejack, the end ladders, the toolbox (underneath).  There are four recessed holes underneath, two on each side, which appeared to have screws in them, and I loosened them (but none will come all the way out).  The shell isn't budging ;-)

Can anybody provide a hint or two what to do next?  My web search has not turned up an exploded drawing; if you know of one, that would probably be a great help, too.

Thanks in advance. . . . !