Achow101, thank you for your kind instructions.
Given that I have recovered an unsent raw transaction and posted a redacted version of the output above, is there anything obviously wrong with it? I have verified that the number 'MyLedgerAddress' is the correct public key for my Ledger wallet. I won't hold you responsible if I lose my bitcoins, but would be grateful if you could tell me if there is anything obviously wrong with it or if there is any advantage to trying to make a raw transaction from scratch, in the way that you describe?
It could of been issue with the way the keys are imported and exported and with the wallet in question being a much older wallet you are attempting to use now there may be issue from the older version of core to electrum.
You can thank the forks for that one.
also make sure it conforms to BIP62 strict DER encoding was introduced since the early version of core.
https://github.com/bitcoin/bips/blob/master/bip-0062.mediawikiGlad you got your coins moved safe.