Stitch Two Musescore Files? Or, copy-and-paste with Time Sig. Changes + Dynamics?

In the past, I've encountered problems inserting measures near time signature changes. I managed to screw up a pretty large document today, and before I copy-and-paste my way to the loony bin, I'd like to canvass the experts' opinions as to possible workarounds.

I have the following two files, and I'm curious if there's any known way to stitch them together into one continuous file. (?)

Also, should Ctrl+C copy dynamics as well? Does copying dynamics, hairpins et al require any special actions?

I'm using version 1.0, revision 3996, on Ubuntu.

Thanks for your attention! Cheers,

Kip