Yes. Our main (brick) part of the house is 1825. The clapboard addition is 1840-1860. They really muddled with the house again in 1914 turning it into a two family and a lot of the trim profile is from that period in the modified dining rooms and addition. I gutted my kitchen in the clapboard section (plus other renovations - move main staircase, add mudroom and half bath, new electrical, plumbing, HVAC, etc) and was having a hard time deciding on trim style. Most of the brick public rooms has 6" highly detailed trim. If I went that route I would have to buy 2 custom knives to have the trim cut. The addition and dining room had 1910's style trim which is in stock at good lumber yards here. That was an easy decision for me. For the modifications in the old section of the house my contractor saved all the trim and had enough for the renovations.

What really bothers me is that the dining room in the brick part of the house has the 1914 trim, moulding, etc. Totally out of place. No one notices it but me. I ran out of steam and just couldn't deal with any more on my plate during the reno. I WILL change it - after phase 4 is completed. That's probably not going to happen until we retire or win the lottery :(

Absolutely. Happens all the time. Our house was built in 1885 and enlarged in 1910 and some parts remodeled 1925ish. The woodwork in the original part of the house is much more detailed than in the 1910 addition. Some of the 1920 changes, which occurred mostly in the addition are impossible to distinguish stylistically. The original woodwork was faux bois finish and most of the 1910 trim was actually painted white right from the beginning.

One of the more interesting Architectural Digest projects I recall was created to look like a 19th Century residence that had been added onto several times by subsequent owners. The architects actually created a "story" for the home. I don't know if they went so far as to do era-correct interior trim.

Our Living and dining rooms look older than the rest of our house because they are 1919 original. And they will stay 1919 original. Our master bathroom was intentionally mucked up in the1980s by a previous owner and it looks horribly out of place (on our to do list). Our kitchen, which we redid in 2005, looks 1930s and we went with that era intentionally. I would be thrilled if our entire home looked 1919 original.