I have both the models for my treasure chest in the same project file, they both show up in the PWS. However, they're in separate windows and I'm not sure how to combine them into the same window, other than using cut and paste or exporting a model and then reimporting it into whichever window I choose to be the active one. Is this how it's done or is there something obvious I'm missing?

That are the two ways which make sense... (as easy as it'll get... Copy&Paste...), so that will not bring bones etc. over... than you need to import one into the other).
What do you want to do? These are really easy actions... you want to have them in the same modelling-window, right?

Or do you just want to animate them together? Than you just have to create a choreography and drag and drop them on the new chor...

See you
*Fuchur*

Yeah, I just wanted to have them in the same modeling window. I just cut and paste the one into the other, seemed like the easiest way to go about doing it. Just wondered if there was a better way.

importing one model into the other is another way, and you will import the bones, poses, relationships as well.

Also... in the PWS you can drag one model onto another to add it to the second model.

and to complicate, create a new choreography, delete all objects, drag the models and export as *.mdl

and to further complicate... make a new action with model 1, drag model 2 into the action. This is a powerful feature of A:M. Keeps the models in their own windows for editing later, and is really great when adding a 3rd... 4th, 5th or even 100 more models. Then to activate in the chor... simply drag model 1 in, and drag the action onto it. Done!

Great tips all around! I've been watching Barry Zundel's tutes and there are some amazing drag-and-drop and copy-paste shortcuts that he uses that are jaw-droppingly amazing to me. The depth of A:M is really awesome.