The eyelets are not the same size as guide eyelets. They are for the front axle and wheels.
The eyelet is shaped similiar to a guide eyelet. It is tubular and has flared portion, it does not taper at the other end though. It fits over the axle. The Cartrix axle is sized inbetween Slot It's 3/32 (2.38) and Ninco's Standdard (2.48). The flared portion of the eyelet has a fitting on the body that it sits in. Once both the eyelets are in place they limit the side to side travel of the front axle and wheels.
There is probably a picture somewhere that shows all this very well, but I don't have one handy.
and brass is too difficult for you to work with, just get a chup-a-chup stick, cut a piece about a 1/4" long, and if needed, drill it a little to fit over the axle.
But I think you'll find it slides over the axle as it is - hollow is about 2.5mm diameter inside, so glue it in place with some superglue - a few pennies for 2 1/2" inches of axles spacers ready for cutting to length, and they throw in a free candy . . . gotta be a good deal