Dang Q! I can't believe you managed to find the potential source for "tongue-in-cheek." Interesting stuff.

The 1748 reference seems to have a different meaning (showing contempt) rather than the way I interpret it today (joking, or not being totally serious).

The 1798 novel quotation is interesting but here we have no statement of context (joking, insincerity, or even contempt). So I'd have to know what came before "by winking..." to see what the actions are trying to convey.

Regarding "d'door" or "t'door" - thanks for the info. I'm glad I'm not alone having difficulty with this. I've listed to just that portion of the song a thousand times now. I couldn't detect anything before "door," so I put "the" in parenthesis to indicate, obviously, that I imagine "the" ought to be there but wasn't articulated in this version of the song.

PS- Notice I'm no longer "Guest, Wavery." =)