B'Man, I find a lot of music in thrift stores, yard sales and used record stores. It takes time, but the occasional gem makes the search worth it. Also, I believe there are collector's papers which feature ads, and there are many music sites and auctions rycheer on the web. Good luck to you.
BTW I am glad there is another fan of the Travelers 3 out there. If you are lucky enough to find their 'Live! Live! Live!' album, the last bit of applause on most cuts is that of your humble correspondent in his youthful, smart-ass days.--John