I purchased a set from someone that is made out of nylon windbreaker material. Very light and works great.
On 2 planes now I'd installed them. I just take a set of Tyvek coveralls from the Home Depot paint department, cut the sleeves off just above the wrist and about 8 inches up the sleeve. Then zip tie it around the pushrod and make a small circle of aluminum the size of the sidewall opening and glue it with RTV / pop rivets in place to hold it to the sidewall.
Here is a pattern I downloaded a long time ago. Me and my friends have made a dozen or more from this pattern!
https://imgur.com/xkGGUpG
Thanks goes to Fred.Stucklen.
Here are notes and photos of boots being constructed using the above drawing from Fred:
http://home.hiwaay.net/~sbuc/journal/cold.html#boots
Mine have been flying in the RV-6 for nearly 18 years and continue to work as designed.