A question about creating custom models

A little thing I do in all my maps is to create a little reskinning of the chalkboard model to have a little doodle by the Heavy. In previous maps, I would normally just rename the skin to chalkboard01_skin1.vtf and pack it into the bsp with the vmt to override the normal skin in the map.

However, I would actually like to be able to use all the normal chalkboard skins in my current map in ADDITION to a little gag one, so I figured I would try my hand at creating a separate chalkboard model and having all three chalkboard reskins I've done as separate skins for the chalkboard. I put in my skins as chalkboard02 under props_2fort, renamed everything, and copied the original chalkboard01 model and renamed all of its files to chalkboard02.

The chalkboard02 model will show up properly in Hammer, but it only uses the chalkboard01 skins. What would I have to edit to get the model to show all the skins correctly? Or is there any way I could edit the original chalkboard model to have these three skins show up as skins 2, 3 and 4?

EDIT: Erm, wait, I meant to put this in Questions and Discussion. I would appreciate it if a moderator could move this for me. :U

I've tried opening the mdl file for the chalkboard in Notepad and editing the skins the model will access, but apparently this causes any map to make Hammer crash the instant I load it regardless of whether or not the model is in it.

Horrified me at first because I thought I would be completely unable to use my map, but deleting the offending file fixed everything. So I guess, in any case, that I will have to edit the mdl file to call to the vtfs, but how would I go about doing that without similar effects to this?