This episode later had two wrap-arounds for it to be shown with later seasons - one with Arnold, and one with Al. The version I saw of this episode was the Al one, though shown as part of the second season.
We get one of our rare looks at Fonzie's original appartment before he moved in over the Cunninghams' garage in the third season to bring him to the centre of the action more.
It is very evident at this point that the writers were responding to the character being so popular and bringing him to the fore much more, as the episode revolves around him.
It also marks the last appearance of Chuck; with the episode being re-packaged for later seasons, it stands as the only real reminded later on that Chuck existed.
Although it's a little sweet and sappy, as it's Christmas it can be forgiven.