I bought mine from here:
KINOKUNIYA BOOK STORES OF AMERICA CO., LTD.
1581 Webster Street, San Francisco, CA 94115, U.S.A. 415-567-7625
They carry some Japanese gun books and magazines, along with a lot of other Japanese stuff. The Tokoi AK and M16 books can be special ordered. Book info is as follows:
AK-47 and Kalashnikov Variation, Tokoi and Jimbo, Dai-Nippon Kaiga Co, Ltd., 1991, ISBN4-499-20582-4 C0076 P3900E
M16 and Stoner's Rifle, Tokoi and Jimbo, Dai-Nippon Kaiga Co, Ltd., 1991, ISBN4-499-20567-0 C0076 P3900E
Both well worth the $53 cover price (in 1998). Pictures superb and unequalled by any US book or mag. A lot of rare variations shown that are not found anywhere else.