Vigesimal Numerals

I want Senyecan to have a completely vigesimal system (not that I
would ever be able to use it!).  My problem is in finding (or
creating) names for the "teen" numerals.  I googled for "vigesimal
numerals" and received a great many hits concerning the Maya
language.  However, even though the Maya calculated by means of a
vigesimal system, the names for the numbers 12-19 were based on ten.
They do have an unrelated name for 11, buluk, which I found to be
very interesting.

Is anyone acqauinted with a vigesimal system wherein the numbers 11-19
have their own names, names not based on ten?

Thanks.

Charlie
http://wiki.frath.net//user:caeruleancentaur