You're welcome for the ads & info, Brian & Declan!
Brian, the 3-in-1 was only made for several years, so either it had a problematic design or had limited appeal to consumers.
Further searching led to finding one more model-type introduced in 1967—102-A with small nozzle wheels; see attached ad. I also included a Penncrest Lightweight model ad and attached it. Penneys in that era sold the Regina and Hoover versions, too—not necessarily at the same time. From what I have seen, the chain carried 2 models of Penncrest/Eureka Lightweight vacuum cleaners—one in 1967 & 1968; and one circa 1971—based on the different nozzles.
Another observation I have made of Penncrest floor & surface care appliances is the model number system. From 1963 to 1967 it was alphanumeric, beginning with an 'A' followed by 3 numerals. Then it changed to a 4-digit system. In fact, some cleaners have both designations on their ratings decals.
Photos:
1. 1970 Dec 7 LEWISTON DAILY SUN Models 2010-A, 34-A, 102-A
2. 1968 Feb 15 PITTSBURGH PRESS - Penncrest Lightweight model
