MFORTH's interpreter doesn't understand double cell numbers

Ending a number with '.' as many Forth tutorials suggest works to put a double-cell number onto the stack doesn't work here.

MFORTH's INTERPRET calls NUMBER? which seems to always truncate double values, despite >NUMBER being perfectly capable of handling them. 

I'm trying to fix this myself but it's slow going trying to learn the language and take apart its brain at the same time.