I can try to do this but in need some indications from you
1. You say
**Here is the encrypted seed from my 2013 elctrum.dat file : "8d3kJQ7jPs+OjaQ10qxVoHGDGqHIv9rMCnQW64Q5eJ6tDctzf5ZeiN2oHKEzQFEs0Y+9yntOTDr7OMBpl//FPg=="**
then you say "I do have the seed"
If you have the seed then the electrum wallet can be recovered and after recovering you can choose a new password.
(read here
http://docs.electrum.org/en/latest/faq.htmlI have forgotten my password. What can I do?)
2. If you remember something about your password tell me please what you remember.
if this above is your password
8d3kJQ7jPs+OjaQ10qxVoHGDGqHIv9rMCnQW64Q5eJ6tDctzf5ZeiN2oHKEzQFEs0Y+9yntOTDr7OMBpl//FPg==
and you need it (cannot recover your wallet from your seed, and cannot choose a new password), this is doable from what I have read on the internet.