Beam me up Scotty! Star Trek's Simon Pegg looking good in an Ames Bros Big Bear Tee.

We only offer sizes S-XXL in Big Bear at this time, :(

I’ve been looking for the big bear T in size 3xl or 4xl for my BF.
Where can I purchase in this size?
If it doesn’t come in that size, am I able to purchase the decal and have it put on myself?
Thx