I suggest make a new server, create a new empty repo, and then use the commands from these posts using the directory structure from your old disk when mounted, to push it to the new server.
Once you get into one of the long random numbers.git directory, there will be a config file in there which is a text file. In here you will be able to find the name of what the repository was on your old server. An example from mine:
root@gitlab:/var/opt/gitlab/git-data/repositories/@hashed/45/23/4523540f1504cd17100c4835e85b7eefd49911580f8efff0599a8f283be6b9e3.git# ls
config description HEAD hooks info language-stats.cache objects packed-refs refs
root@gitlab:/var/opt/gitlab/git-data/repositories/@hashed/45/23/4523540f1504cd17100c4835e85b7eefd49911580f8efff0599a8f283be6b9e3.git# cat config
[core]
repositoryformatversion = 0
filemode = true
bare = true
[gitlab]
fullpath = test/test
that fullpath option will be the group/project name where it existed. Then you can push it to the appropriate place using the commands from the posts I linked that have helped others in a similar situation who didn’t have backups.