no i havent the dat file old file
If your wallet was created in v1.9.8 as you described:
Its wallet file isn't named "
electrum.dat" but can be anything that doesn't have a file name extension (
no '.dat').
You can try looking for "
default_wallet" which is the default name but if you created more wallets, the name can be anything.
Check the drive where you found your seed phrase and encryption password backup.
If you found possible Electrum wallet files, you can try to open those as "
text",
The contents should start with "
{'addr_history':" whether it's encrypted or not because the seed is the only data that's encrypted in that version.