Well, I was at my local Shaw's a few days ago and they had Meyer lemons as a new item. Not very well known in our frigid Massachusetts, I can tell you that. They are a slightly smaller version of my beloved lemon; juicier, with fewer seeds and a thinner, edible rind of a more intense yellow. Less tart. They also taste a bit like tangerines, and are very fragrant.
Take your sliced white bread, preferably bought that very day. Italians do not use whole wheat or crusty bread for tramezzini. Carefully cut the crust to avoid jagged edges. Spread both sides with mascarpone. Cover one side with smoked salmon. Very thinly slice the Meyer lemon, rind and all. Cover half of the salmon with lemon slices. Place capers on other slice (I used non pareil). Carefully close without having everything fall out and roll all over the place. Cut in half (no jagged edges!), either in half or diagonally. I did not add salt or pepper.
I intend to use my new Chinese lemons in other things. So far, I've made a vinaigrette for my salad (yesterday) and put a slice in my gunpowder green tea (this morning). Stay posted.
(in the photo, typical tramezzini in an Italian bar)