I love sandwiches but don't get much bread these days... bologna and pickle spread would be very much like Olive Loaf. a personal fav most people groan at. My husband can make the most amazing grilled sandwiches full of butter and other things, I usually go for toasted versus grilled.
Reuben sandwich open faced -- half the bread! Love rye bread in general, if I can get it as a toast option I like it with Orange Marmalade. Another rye classic, braunschweiger (liverwurst with bacon) on dark rye with crisp green lettuce and red onion slices.
We had some left over keto buns recently and some smoked salmon along with a jar of capers and an onion in the fridge... also would have been nice on rye bread.
Weird things that make sense -- salmon sandwiches from canned salmon (made like tuna salad), better with about half hard boiled eggs, lots of green onion tops.
Our local bakery, Franz has a Keto bread and now buns that is reasonable for us to have. Prior to that, their white whole wheat was my best choice. Only problem is it doesn't toast at all well, turns hard and crisp more like a cracker. It grills nicely though, either using mayo (on the outside to help toasting -- try it, it works) or butter/oil.
Of the things I miss most in my new way of eating is everything bagels. The 1/4 bagel I'm allowed only makes me want more, I'm better without.