Yes, importing is available via the following options: from clipboard or from file, optionally in RAW.
Btw sorry, you asked before if tx export was possible, for some reason I missed that option before.
Ahh well then, that changes everything! This should (hopefully) be the easiest option going forward then. What I would do is the following:
- Get a list of all the addresses which still have funds on them
- Create a new Electrum wallet, select "Import bitcoin addresses or private keys", and insert all your addresses
- In that Electrum wallet, create a transaction sending all those coins to a regular address you control
- At the bottom left of the transaction window, select "Export" (you might have to select "Finalize" first), and export to clipboard
- Import it from the clipboard in to mSIGMA and (hopefully!) sign it
- Export it from mSIGMA, import it back in to Electrum, and broadcast it
I feel like that was VERY close. Did all the steps on the electrum side - works well.
When trying to import the transaction with mSIGNA I get the following error and immediately aborting "invalid signature" - if I just select "import transactions".
When trying to import using "import transaction (raw)" I get "Push operation exceeds data size".