If I can show I still have my old login for BTC guild and prove I was mining would the old admin give a crumb of compassion if he saw that I never got my coins? I just didn't follow up and knew not about the project shutdown.
I would say it is very unlikely they would refund you coins that you forgot to take out.
I would agree with this take. That is a long time and with Bitcoin's insane valuation increase, no matter how often people want to repeat it, 1 BTC does NOT equal 1 BTC. At best, you could probably sue someone and try to recover the USD amount, but I'm certain that wouldn't be worth the effort for you or you wouldn't have left it there in the first place.
People don't seem to understand that Bitcoin isn't like the dollar. When you spend Bitcoin, it is legally valued at the USD rate at the time of transfer. You can't expect someone to honor your BTC price from a decade ago.