Frederick Post model 44CB220[1972+]

25-Scale All-Plastic Engineering Rule (Rietz)
Teledyne-Post model 44CB-220 [1972+] (Some [1972] marked 1422)
Hemmi model P262

This appears to be another example of changing the model number after the slide rule had been manufactured. Specimens with both model numbers exist but I'm sure Teledyne-Post never sold this rule under any model number other than 44CB-220.

The scale set is "Rietz."

1972 Teledyne-Post Slide Rule Catalog

Top: Teledyne-Post 1422. Date code "UJ" (October 1970)
Middle: Teledyne-Post 44CB-220. Date code "^XF" (June 1973)
Bottom: Backs of rules are identical.

1972 Teledyne-Post Slide Rule Catalog
Top: Teledyne-Post 1422. Date code "UJ" (October 1970) Middle: Teledyne-Post 44CB-220. Date code "^XF" (June 1973) Bottom: Backs of rules are identical.