In Palemoon:
Bookmarks > Show All Bookmarks -> Import & Backup - Export HTML... - to a location you can easily access
then in Firefox:
Bookmarks > Show All Bookmarks -> Import & Backup - Import HTML... - from an HTML file -> where you saved the file you exported from Palemoon

Thanks for your prompt response. In (my copy of) Palemoon 5.0, the sequence below isn't present so I don't seem to be able to do any HTML export; there's no entry for 'Show all Bookmarks'.

Bookmarks > Show All Bookmarks -> Import & Backup - Export HTML

In the File dropdown, there is an entry for Import... but it's inactive. Any suggestions? Thanks again. Stan

Aw heck, I just noticed that Palemoon 4.0 changed the wording of that menu item back to what Firefox used before Firefox 4.0 = Organize Bookmarks

I don't even use the menus to open the Library window, I use the keyboard command to open it - { Ctrl + Shft + B }.

Thanks again. I also got this info from Palemoon's Troubleshooting section. The sequence is: Organize Bookmarks > Import & Backup > Export Html All very helpful.