I bought one a Toledo one year which was a bit small do I made another larger.. They are both made from brass tubing with kerfs cut into them at angles and then mounted to a short dowel.
I cut my holes before building but sometime you end up having to after the fact such as the BUSA bristol M-1 I bought that didn't have holes for the servo leads and.... I have to remove some of the bottom covering to do so.
Nice clean holes by the way.