I literally saw a modeling knob on ebay before when searching for a V1 Variax to buy, but that's probably a very rare occurance.
If you do find it, put a little glue on that sucker next time.
Does your modeling selector still work though?
Yes, it works fine as long as you know where you are. Once you get to Custom 2, it keeps moving and eventually gets back to Custom 1. I am assuming that is why the leg is on the knob to give it the finite range.
I found the attached pic on this forum in a search. It shows the leg on the right side of the pic.Attachments:
- knobs4.jpg (71.4 K)
i'd contact support, i'm sure they can still get that: http://line6.com/company/contact/
(they're closed this monday... so you wont be able to call them or get a response until tuesday)
found this... http://www.ebay.com/itm/Line-6-Variax-Modeler-Knob-/221181850344?_trksid=p5197.m1992&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D14%26meid%3D5668007416027339918%26pid%3D100015%26prg%3D1006%26rk%3D2%26sd%3D300862479223%26
However, it doesn't have the plastic leg on the bottom. I am assuming the 300/600 series share this. The shaft of the pot has the D-shaped top so it's keyed... and the leg keeps the switch from just continually spinning. The one on eBay looks like it's knurl for a force fit type deal. Definitely going to put a drop of Elmers or something on there when I get a new one.