What did you make them out of?? That is interesting im a faber i love making my own parts and tools![/
I did it twice but am only claiming one attempt since the first time was so basic. My down and dirty version when I was a youngin' was opening up the areas a bit on the brackets (at the time, I viced the cover and drilled) and basically went to the hardware store and bought small black rubber grommets with a workable OD/ID (was working with 7mil wires back then). Cut them just off center and slid the larger side (x8) on the bracket and dropped the wires in. As far as functionality, it worked well.
The second time, I used some old Moroso wire separators and spent too much time reshaping them and grinding the Moroso name off. Enlarged the bracket openings to match the Moroso openings (now up to 8mil wires). Ended up adhering one to each side of the bracket and filled in the gaps with some sandable plastic resin (from another project). Did a little sanding/refilling/sanding. Afterwards, shot prime and OEM rattlecan paint. They looked pretty good.