Amati/Cerveny model descriptions

[sailn2ba]

Have any A/C models been discontinued? . . .perhaps from before the 1960s?
The models I've looked at have all had LLL-NNN-xxx.. numbers, and to start the discussion, I've observed that the 1st 3 letters denote the builder, (A)mati or (C)erveny, and the key, BB, CC, F, EE. The 2nd group of 3 numbers seems to use 6-- for brass, 7-- for red brass, and 8-- for clockwork springs. The second digit seems related to the bore with -8- at 20 or 20.2mm and -0- and -9- for 21 or 21.1mm. The 3rd digit might have to do with wrap or some combination of wrap and bore, as the 601 is designated a 5/4 horn, the 691 (a little shorter with the same bore) as 4/4, and the 693 has the same bore with the "piggy" wrap. That --3 designation is used for 3/4 size horns in other models. Finally, suffixes are added in a third group to designate nickel-silver parts, valve linkage options, etc.