Small circle shear and spinning mandrel material

[Ohio]

I've been practicing my metal spinning and I'm thinking I need to cut my own spinning circles and perhaps make mandrels/forms out of something other than wood.I did a search and didn't exactly find what I was looking for, so I thought I'd ask. This is a two-parter, so please bear with me.

1. I need to cut non-ferrous sheet metal circles probably no thicker than .050" with a diameter between 3"-10" . I was wondering if anyone has built a Riser Circle Shear or Daniel Remer Circle Shear by modifying an inexpensive Harbor Freight tool. If so, how is it working out for you and was adapting the tool hard to do? If you have one that you never use, would you consider trading/selling?

2. I've turned my own mandrels and follower blocks out of wood or engineered material (I think it's medium MDF, but I don't remember and am too lazy to run into the shop right now). It works well, I have confidence in my glue-up abilities, etc., but I'm wondering if there's a synthetic that may be a bit tougher. (At some point I may make forms out of steel on my metal lathe, but first things first.) A Robert Sorby instruction manual I have suggests Nylatron, but I'm not familiar with it.

Does anyone have a material recommendation? I need to be able to turn it on a wood lathe, install threaded steel (like a nut) in the mandrel to thread onto 1"/8 headstock and rod in the follower block to place in a live center on the tailstock, and not cost me that extra kidney I've been saving.

Thanks.