In the 90's scuzz my Workbench 3.0 was a hybrid too as I used to nick all the latest libs and devices etc. from AF and CU cover cd's. Ahhh... they were the days!
I wouldn't rely on any of your Amiga OS installs to be legit unless you have installed them yourself, fresh from the original unmodified OS disks. The reason I say 'unmodified' is that you have to be careful as some people did modify their Workbench disks, either deliberately or by accident.
Been chasing down a Parnet conflict all day on this beast. I have used the same config and loaded everything in the same drawers on so many machines from 500s to 600s to 1200s to 4000 and never had an issue, but this 2000 refuses to play ball. I have the Checkmate logged in no problem and finds all the drives and I can transfer. But the 2000 just hangs on finding network. If I use the tool that came with the machine it goes through a different route and concludes it proceedings and places the Network icon on the desktop but its empty. The tooltype etc all are working with the support files.. just won't communicate with the Checkmate. I have checked everything so many times. Been at it all day... I'll probably have another go before bed.
Anyway, I never really trust installs actually on machines, as I know from experience my Workbench has grown and grown over the years. This one on this 2000 is as you see it cus I don't have the disks for it. I kinda sense when folk upgraded the Rom they rarely destroyed all of their previous OS given that it probably ran a lot of their software. So they kinda merge and blur together.
Anyway.. back to me Parnet. Annoying.