Bill, I just repaired my bedroom slide floor bottom because or wear issues and misalignment issues. Contemplated Delrin, but went with 1/8" Aluminum sheets grade 6061 T6 Structural grade. The strength of the aluminum is 14,000 psi and Delrin was at best for what I could find, 9,000 psi for 1/4". Neither will rust and aluminum was cheaper for me and readily available. Also installed 3 plates in the same configuration to the living room slide for the same bottom wear and alignment issues.
As for my bedroom roller it is still working just fine, just had to address the floor wear.