What I can't tell from the information provided is if it necessary to sign each of the inputs separately, or whether you can just sign the entire tx with one.
So two examples:
- Input 1 came from address A and input 2 came from address A.
- Input 1 came from address B and input 2 came from address C.
For example 1, my assumption is that I could just use
bitcoin-cli signrawtransaction RAW_TX
but for example 2 I would have to use
bitcoin-cli signrawtransaction RAW_TX  ["ADDR_B_PRIVATE_KEY"] bitcoin-cli signrawtransaction PARTLY_SIGNED_RAW_TX  ["$ADDR_B_PRIVATE_KEY"]