Glenn,
I recently acquired a Curtis K5 "Lil' Bugger" keyer with the 16-pin 8044 IC. Since I'm a mode B kind of guy, the thought was to extract an 8044B from an EK-1 and swap out IC chips. The 8044B seems the rarest of the bunch, probably because the 8044ABM came about shortly after the 8044B's production in 1981.
Another alternative is to find an 18-pin 8044BM which is also scarce. Get this: in a pinch, John Curtis suggested that the 8044AM and 8044BM can replace the 8044 and 8044B by simply letting the two extra IC pins hang off the 16-pin IC socket! The extra pins are used for the speed meter circuit. The pinout between the 16 and 18-pin versions is otherwise the same.
I'm also on the search for an ancient MFJ Econo Keyer I model which uses the 8044B. Strange, but it too is rather scarce. However, its progeny (the model II and III models) are plentiful but don't use the 8044B.
Although I could redesign the K5 using any one of several PIC chips (PK series, TiCK, K12, etc.), I would really like to preserve its originality and hence the reason for my 8044B search.
Paul, W9AC