tinocorp.com sells their own mats; maybe find out who they used.
Would the shipping really be so bad for 8? From memory they're quite heavy I spose but even so.
I love the implication that there is a professional, capable and reliable industry making these things ... 6,000 miles away! There needs to be a newly-coined word to refer to this particular sense of frustration: "Why doesn't my town/state/country have a single acceptable example of this perfectly commonplace and standard commercial operation?"
I wonder if it's the quantity that's scaring printers away? There's an awful lot of overhead involved in setting up a silkscreen to do 8 mats...
Any screen printing shop should be able to do these for you. I apprenticed as a screen printer a long time ago (roundabout the time of the First Crusade - I had a note from my uncle, Pope Urban II excusing me from gym class). We would print oddball items every so often.
Although ink technology has no doubt changed since medieval times, I'd suspect that UV-cured ink would do the job nicely.