Got a sink today for the downstairs bath. Upon realizing 2 of 3 bath sinks had been replaced around '39-'50, it became glaringly obvious that they did not match the other fixtures or the house. A lot of time when working on old houses, I aim for cohesion. Along with updating the plumbing, foundation, electrical etc, I try to clear away the years of random fixes and "updates" done to the house because they are usually crappy. If I can afford to buy the house, it's usually so ugly and crappy that banks won't even finance it because it's unliveable.
My logic for making the house cohesive is simple - I use the original style as a guide. I usually love the original style of houses made in the '60s or before. I just have to undo the "updates" they did in the '70s, '80s and '90s which match the style of the time but usually look dated in retrospect. It's easy to make the house look right - you just have to go with the flow and not force hard lines of modernism onto your craftsman bungalow, for example.
I'm ranting again. Anyway...
Sinks of the 1900s to 1920s and 30s are round. They have round, large radius edges. All the way through 1928 when Crane came out with first colored porcelain bathroom sets (which are super cool and I want to use for the master bathroom), they were round. I don't know if this is because they were usually cast iron during this period instead of solid porcelain or glazed steel, but it may have something to do with it.
Here is the original 1927 tub. Round round round. Round edge, round basin, round knobs: