Late 80's ms36-42 ghs

Hey folks, quick into. I'm the landscape and grounds manger at a university in washington DC. Worked for Disney for a while and owned my own company for a stretch as well. I am very familar with the Walker mower. Love them. I currently own a late 80's MS36-42 GHS with the 42" deck with the 11hp briggs.

I have repowered the walker once since I owned it in the last 7 years. when I bought it the motor had no compression so I did a repower... The 11hp briggs are getting hard to find...the mower has over 7000 hours on the hour meter, and the meter still works

I have two things I'm looking to do. The hydros seems to be getting "tired" when its cold it works fine on all levels. but once it gets warm, when going down slopes its almost like the mowers wants to coast and overspeed the hydros, going up hill is fine warm or cold. so I'm thinking maybe its time to rebuild the drive hydros. Walker does not sell parts to rebuild the hydro they only want to sell me a complete hydro.. GRRR.

The other thing I'm thinking about...and don't tar and feather me...

Electric. the walker has a nice configuration/ space to drop in an electric motor and some deep cycle batteries...

Has anyone thought about doing this?

marc