1) Make a backup of the wallet.dat file before doing anything.
2) Do #1 again.
I know about backup's is first what i must... in all situations
Did you try starting Bitcoin Core with the -upgradewallet?
You should also be able to extract the keys using pywallet
Yes, I tried to run the client with all possible variables ... to no avail. Dump keys with all possible applications also does not result in what it should.
I can probably get you an old working windows build, but since I am just an anonymous person on the internet you really should not trust me....
I am aware of this ... in this situation, however, I have no choice but to be grateful if you can find it!
Yes, I know there are source codes packed from every version. As I mentioned - all-day compilation attempts on both linux and windows were unsuccessful due to the dependencies probably used at that time, which are now either unavailable or collide with anything else. From these old sources I am not able to compile a working version ... this result is the topic created here :-)