Is it possible to create a transaction spending coins from 2 differents Armory wallets ?

The situation :
- I had coins on an old wallet that I moved to a new wallet because of the security problem a few years ago
- Some addresses have been spammed with small amounts of satoshis, barely above the dust limit
- Usually I deal with this by merging them with the coins that I have on the same address and sending them to a new address, with a 1s/vByte fee (only if the resulting UTXO is higher than the old one).
Example : 1 BTC + 536 sat - 257 sat fee => 1.00000279 BTC on a new single UTXO
- I am very careful in never mixing dust from different addresses (or chains of adresses) so as to not link the addresses together
- Today I have dust on the old wallet, which I would like to merge with the corresponding address on the new wallet

The problem is that Armory does not let me do that because I can only select coins from a single wallet (both wallets are on the same hot and cold machines)

Is there a way to do it properly ?

I could export the private keys from the old wallet (which is mostly empty) but not from the new one.