Check FontSquirrel, which is specifically for commercial-use fonts. They may have the same font, they may have a better contact info. Or not. This is a problem with the font-use issue, people who release it as personal-use only or without any licensing info, then can't be contacted when someone actually wants to do the right thing and try to pay for its usage.
If the shirt is just for you, I'd say go for it. If it's for commercial use, at least spend a little more time trying to contact the owner so you can definitely say "I tried".
If the shirt is just for you, I'd say go for it. If it's for commercial use, at least spend a little more time trying to contact the owner so you can definitely say "I tried".