If your motorhome steadies are slipping a good clean may be all they need. I cleaned the steadies on our old Hymer and now they are working a treat.
This video may be useful.
If you want more info about owning or buying an old motorhome, have a look at:
www.classicmotorhomeowner.com

You don't need much to complete this job but here are a couple of affiliate links to help you find what you need.

You can get a wire brush here:
https://amzn.to/2JgHUYD

Grease
https://amzn.to/2YDQBBw