SOLVED!
Once Bitcoin Core finished mapping the blocks. Bitcoin appeared in my wallet. I can now add BTC to that wallet, and Armory backup will still be valid, right?

I have closed Armory and started Bitcoin Core, it says it is not synchronized with the network. It is at 53%. I will let it finish the synchronization and get back to you.

I don't know where do I see that. In the lower right corner it says 107812 blocks.

0.96-beta-a3d01aa722
Bitcoin Core 0.14.1 64-bit
Windows 10

Armory says it is online [Connected].

I have restored a wallet I have created in 2014 using Paper Backup. Balance shows 0.0 BTC, but if I go to list of addresses:
- List of used addresses is empty
- If I check list of Unused addresses and select an address there, I see BTC there.
- Tried Rescan Balance, but Balance remains 0.0

How do I get my BTC visible in the wallet?

+1

Yes, can something similar be done for PTS?

Great work, mate!

Is this for metiscoin only or can it be used for any other coin?