I’m personally inclined towards RD1 in Albany, ad a 1.5m lenght will set you back a mere $6.49 for a 10mm thickness, and less for thinner. The rods also tend to be a bit less whippy than the ones used for the kites.
But like everything, there’s a lot of personal preference involved.
If what you have is effectively a flat disk with a hole in the middle, you could try getting a piece of pvc pressure pipe (offcuts from any plumber are the way to go - don’t go to stores, they will rip you the smeg off), maybe two-three times the length of your centre hole…
Ah fuggit, pictures ftw

Just bear in mind that this kind of handle won’t be as strong as a more integrated one, but if you wanted to increase the strength you could put a cloth layer (ie cloth soaked in ados/f2) running over the shield face and handle, as well as over the back of the shield above and below the handle.
If you think it’s worth trying to do a compiled guide, I’ll look at it for the next week. It’s something I was quite keen for if we got the nzlarps website back into more frequent use - especially if it were to be used for articles and such in the vein of Immersion 