When I first got into bitcoin back in the day I used Multibit. I only ever had a small amount of bitcoin, but without going into too much detail I lost a few and ignored cryptocurrency for a while. When I regained interest I found that Multibit was no longer supported, so I sent my bitcoin to an Electrum wallet and subsequently moved to a hardware wallet.

I've just found out there may be a chance of regaining access to the bitcoin I lost back in the day if I can prove that the Multibit wallet was mine. I've been requested to make a small transaction from the same address of the Multibit wallet.

Could I deposit some bitcoin back to my Multibit wallet and send from there, or will there be issues? The max fees are 50k satoshi per kb - is that still sufficient today?

Alternatively, I still have old backups, including the .key .info and .wallet files from Multibit. Can I sweep/export these to another client? Are there problems/risks doing this with a .wallet file? Will I still have the same address if I try to sweep these to electrum?

Any help would be hugely appreciated. I don't have a huge amount but I'd be happy to help out anyone who can assist me.
Cheers

I purchased some a samll amount of bitcoin a few years back and stored them on Multibit v. 0.5.15 - recently I've transferred a few with no problems. Earlier this evening I tried to send some to a wallet and the transaction was seen by 1 peer but not confirmed. After reading online it seems that the fee wasn't high enough for it to be picked up by other peers.

Apparently I need to Reset blockchain and transactions to resync my wallet, but I've been advised to upgrade to the latest version of Multibit before doing anything. Does anyone know if it's safe to do this in Multibit HD, or have I got to download the latest version of Multibit Classic? Will I need to extract my keys or can I use the current .wallet file on my mac?

This might be insignificant but I don't want to risk my coins. Any help much appreciated.

I see the appeal of keeping public data in a transparent network such as Factom, but does anyone else feel it could infringe upon privacy and individual liberties? I'd imagine a lot of people wouldn't be keen on their property portfolio or personal info being easily accessible and in the public domain. Particularly in Europe, where it would conflict with a lot of the enlightenment ideals at the heart of old legal systems...

Views? I'm interested in it regardless, but I just wonder if it's too ambitious or likely to be replaced by something similar, but slightly different.