Originally Posted by Goldeneye
Since I was basically a baby when the L&S&C version came out (and even then this was fairly short lived, as it ran for about 2 1/2 years tops), if I saw it as such back then, I was not very familiar if there were any changes to the regular intro except for the obvious difference in the title card in the intro.
If you google "Laverne and Shirley and Company", you can see the font they used for that title.
There's one variation you didn't include. It's a season 2 variation that credits the actresses coming through the apartment doors, but it says "Penny Marshall as Laverne" "Cindy Williams as Shirley" (including the character names like the umbrella/front steps opening) as opposed to "Penny Marshall" "Cindy Williams". I haven't seen this opening since ABC daytime reruns in the late 70s/early 80s, but I remember it distinctly, because it so clearly indicated it was a season 2 opening as opposed to season 3 (which didn't use the character names with the actress' credits).