Also any dual solder spool holder recommendations (2x250g spools)?
Do you mean dual 500g or 474g/1lb rolls, or genuinely mean the less common 250g/ 0.5lb rolls (i.e. Multicore)?
Can't recall ever seeing a holder specifically for 250g/0.5lb spools (accustomed to 500g/1lb ratings), but 2x 250g should sit side-by-side on a single holder. FWIW, my holder measured at 80mm wide.
I know you stated you don't have access to wood or metal facilities, but this should be a project you could do with a screwdriver or a couple of nails using very thin plywood and dowels for example (i.e. wood from R/C hobby shops or craft stores). Thinking something along the lines of this:
Dual solder rolls holder. Plywood for the base, and nail or screw 2x pieces of dowel to it by one end.
If you'd rather a kit of laser cut parts from acrylic sheet (need a little plastic model glue), the following might be of interest (they can stack):
Solder Spool Holder - KIT (by SpikenzieLabs, and does ship to EU & takes Euro)