Hey Tom,
Well gift shops are a place to ever pass up. In hotels, or airports. I have seen both first and second hand finds from gift shops and a limo was one of them.
Also full blown truck stops or gas stations that may be big enough for the big rigs to fuel up at that sell more than gas. I have one right over the border when i drive into PA that on occasion has some worth wild, scalewise that is, cars in the past.
Just some ideas to throw at ya to think about. :-)
Grimm