Not sure either...
I was listing all files I was aware of: Current, RotatingOldCurrent("Backup" above) and up to 4(*) Backups.
Until now I overlooked the one you mentioned:
I only have at most one of those files ^^ for each character/world. Dunno how VH handles the differently named backup files.
I've never used VH's internal restore feature. Always did that manually myself. :shrug:

(*) this max number of backups can be changed in VH's config/setup -> misc menu.
"X∈{x|0<x≤4}" was just me nerding out and seeing if those special characters work. It's the same as X=1,2,3,4