If there are ROM/EPROM chips fitted in the relevant sockets, then the link(s) would have been moved, which disables some or all of the built-in sideways RAM.
With sideways RAM, yes, you can load ROM files from floppy to the sideways RAM, then as long as you don't power off, that ROM will be available as if it was a actual ROM/EPROM chip. Note however that a small number of real ROMs were written with some protection to prevent use from sideways RAM.
I have also received the ROM that you sent me. Thank you
Due to lack of time, Multiwizard has beaten me to uploading the file.Mark