Network Admin Responsibilities

I’m currently putting together a proposal for the company I work for to become their full-time IT administrator. I’m the unofficial IT admin here mainly because the company is relatively small. 40 PC’s and 2 servers. I support all the pc’s and the network, manage the back-ups, and research IT spec’s.

Can anyone give me some ideas of types of responsibilities I could take up to validate my time as a full time IT administrator?