A quart container of DOT 5 from my local NAPA is around $16 right now and that will do a complete stock M715 system dry.
I went to a local fabric store to get my seat foam and did away with the horsehair and springs because they were so badly deteriorated. I cut a plywood bottom and used the foam on that with new canvas covers. Just be sure when you get your foam you buy high-density foam. The cheaper furniture type foam compresses flat very quickly and doesn't last very long.
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