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.