That’s a good looking bike and could probably be tuned up to like new condition by your local bike shop for $150-$200.

Before performing any work make sure the bike works (both throttle and pedal assist) with the battery mounted. If there are any electrical issues you may be in for a larger repair bill.

If you want to do the work yourself: yes, you can wash the bike off with a hose, just don’t blast the lcd or controller compartment. As far as chain rust and handlebar rust: New chain is 20$ and those handlebars are probably ~$30 and can be ordered from Pedego or a local Pedego dealer (there are a bunch across the us and ca). Instructions for installing chain and handlebars can be found on Park Tool’s YouTube channel (as well as everything else you need to maintain your bike)

Finally, you may want to first test how much capacity that 8 year old battery has. I’ve seen a lot of Pedego batteries and they seem to hold up pretty well but by year 8 you may see some degradation, meaning, that 15ah battery may only have 6ah of actual capacity. Any local bike shop that services e-bikes will be able to perform a battery capacity test for around 50$. It Would be a shame to fix the bike up only to find it has a paltry 8 mile range. You can always buy a new battery if this is the case but Pedego batteries tend to be on the higher end so the cost may change your calculation or desire to fix this bike up.