Seidel & Naumann
				Fahrraeder- und Naehmaschinenfabrik Seidel & Naumann AG, Dresden, Germany
				Since 1954: VEB Schreibmaschinenwerke, Dreden, GDR
Models and s/n	Y	M	D	Remarks	Ref.
Ideal Standard
Model A1
up to 200	1900			First German 4 key-rows machine	10
Model A2
up to 1400	1901				7,10,13
3600	1902			Since 1902: "Ideal Polyglott" Models, with multi-language writing (double shift and sometimes only capital letters, depending on the second language), 42 keys up to 200 different characters by combination	4,7,10,13
8500	1903				7,10,13
Model A3
up to 16000	1904				10
24000	1905				10
32000	1906				10
40000	1907				10
52000	1908				10
Model A4
up to 66000	1909				10
76000	1910				10
84000	1911				10
91000	1912				10
96000	1913				10
98000	1914				10
99000	1915				10
100000	1916				10
102000	1917				10
103386	1918				10
Model B
up to 500	1912				10
3000	1913			Some Model B's are also known as Model No. 5	9
6800	1914				10
8000	1915				9
12000	1916				9
14000	1917				9
19000	1918				9
25000	1919				9
30000	1920				9
93000	1926			1921- 1926 machines with large carriage	9,10
95000	1927				9,10
Model C
up to 33000	1920				9,10
43000	1921				9,10
59000	1922				9,10
72000	1923				9,10
81000	1924				9,10
100000	1925				9,10
Model D
up to 101000	1925				9,10
110000	1926				9,10
124000	1927				9,10
137000	1928				9,10
150000	1929				9,10
263000	1930			At 22000 all Ideal Models began to be numbered consecutively.	9,10
275000	1931				9
Model DZ1
up to 264000	1931				9,10
Model DZ2
up to 267000	1931				9,10
271000	1932				9,10
Model DZ3
272000	1932				9,10
278000	1933				9,10
Model DZ33
up to 279000	1933				9,10
500000-528000	1934			Since 1934 all Ideal and Erika Numbers running consequently starting at 500000	9
up to 576000	1935				9
654000	1936				9
743000	1937				9
835000	1938				9
840000	1939				9
950000	1940				9
1005000	1941				9,13
1008000	1942				9
1015000	1943				13
1020000	1944				13
1060000	1945				13
Portable
Erika
Model 1
up to 3000	1910			The three key-rows machine was named "Bijou" or "Gloria" as well	9,10
Model 2
up to 4000	1910				9,10
7000	1911				9,10
Model 3
up to 10000	1911				9,10
18000	1912				9,10
25000	1913				9,10
28000	1914				9,10
29000	1915				9,10
31000	1916				9,10
33000	1917				9,10
36000	1918				9,10
40000	1919				9,10
46000	1920				9,10
53000	1921				9,10
62000	1922				9,10
70000	1923				9,10
74000	1924				9,10
80000	1925				9,10
Model 4
up to 80000	1925				9
85000	1926				9,10
88000	1927				9,10
90000	1928				9
Model 5
up to 109000	1928			Four key-rows, Tabulator	10
126500	1929				10
145500	1930				10
162000	1931				9,10
177500	1932			Set-Tab.	10
Model 6
up to178000	1932				9
203500	1933			Modell M, normal Model 6 and Model S, simplified Model 6	10
up to 528000	1934			new serial numbers since 1934, grouped with Ideal, see above	9
600000	1936				13
680000	1937				13
740000	1938				13
840000	1939				13
950000	1940				13
1005000	1941				13
1008000	1942				13
1130200	1944				13
1146600	1947				13
1166000	1949				13
Models 8, 9 10
over 1300000	1950			Model 8 ended 1950	13
over 1312000	1951				13
over 1700000	1953				13