I've seen so few XX and XXX guns that I am not qualified to answer your questions. I am sure that others will be able to provide answers or at least speculate about the answers.
Here is a little more information on production of XX and XXX guns from the Hunter Arms Company Records:
1890 112 XX and 64 XXX
1891 17 XX and 25 XXX
1892 4 XX and 7 XXX
1893 1 XX and 1 XXX
1894 3 XX and no XXX
none from 1895 onward
It appears that their record keeping improved with time.