An interesting anecdote about this thread:

I sent an email to UWO's graphics standards department to see if there were actually an official tartan. The response I received, just now, was that while there is no official tartan, there is an unofficial tartan on Scotweb's database. The link to it was provided in the email. Ironically, the link was to the tartan that I myself designed, the one you can see in the OP. I've opened a dialogue with the head of the department to see about designating an official tartan for the school.

Thanks for everyone who offered advice. I'm hoping to have this kilt made up towards the end of summer.