I was recently watching the episode entitled Burnses and Mortons Go to New York (1955) on AntennaTV and noticed what I'm pretty sure is a cameo by Carl Reiner near the end of the episode. He plays the waiter that brings the hors d'oeuvres into the hotel room, to whom Gracie is supposed to give a tip (she instead hands it to a guest, of course).

As far as I can tell, the appearance completely uncredited, not only in the original (voiceover) credits where they give the names of the actors portraying the train staff and the reporters, but also in all the online links for the episode that I can find.

I've included a couple of screenshots; am I nuts or is that Carl Reiner?

It looks like him in the second picture, but tough to confirm in the first.

Good eye, if it is him!

I was recently watching the episode entitled Burnses and Mortons Go to New York (1955) on AntennaTV and noticed what I'm pretty sure is a cameo by Carl Reiner near the end of the episode.

You are correct! He's credited as "hotel waiter" in that 1955 episode:
http://www.imdb.com/title/tt0587126/?ref_=nm_flmg_act_87