@ Kevan - the brass tube is a solution to a mistake. Wanted just the piano wire but managed to solder both ends to the carriers and THEN discovered I was way off on the length. Almost impossible to remove the piano wire from the end carriers without de-soldering the components (square tubing soldered in U channel) so why not cut and shorten the wire ends then sleeve the two with an adjoining tube. It worked.
Got the wheel inserts in place and painted. The fronts are resin copies of my clubmate's 3D printed ones for 15" rims. The rear were reduced in diameter to fit Slot It F1 rims.

Went for more rear tire (diameter, width and sidewall aspect) than my Coupe by fitting urethane copies of the Fly March GP rear tires. My favorite rear tire set up for a lot of cars I've built.
Dan