roor, You didn't tell me what color your furniture is going to be... however, since you like the dark stain, I am going to assume you want a dark finish. Firstly, the only stain I ever use is Minwax oil based stain. I use Provincial, English Chestnut and Golden Pecan. I make my own mix using these three colors. When we first built our mantle between the LR and DR we built it out of Poplar. I researched it as best I could (this was before the internet)I was told poplar was for painting and not staining, it doesn't take stain well, as it stains unevenly and looks terrible. (this is true) Firstly, pick out the poplar wood that has NO green in it. The stain will not cover the green. The first thing you have to do is seal it. If you don't seal it it will be a mess and look blotchy and the stain will take unevenly. You can either seal it with Boiled Linseed oil (this is how I seal all my wood now) The waiting time for BLO is three to five days, before you can begin staining. Then your stain can be applied. However, when we did the mantle (years ago) we didn't know about BLO, so I sealed it by first staining it with golden Pecan, then wait a few hours and stain it with the darker stain. Do a lot of scrap pieces (with the golden pecan first, then the stain) to test the color you want. I mixed Provincial and English Chestnut with a splash of golden pecan to get the color I wanted. I got a perfect match with my dining room set. So if you have furniture, you can try and match it, but in my opinion if you can't match it then go darker. After you apply the stain, wait 2 days before the final finish is applied such as Minwan semi gloss poly. Before you apply the poly lightly sand with very fine sandpaper and clean with a tack cloth before applying the poly. I apply the poly (thinned down slightly with turpentine) with a rag. I apply thin coats, waiting a day between coats. If it is too shiny it can be sanded lightly with 000 steel wool to the desired finish. If you thin down the poly and apply with a rag, use four to five coats. Note: applying the poly with a rag, give you more professional look. You'll have more control to achieve an even finish -- without heavy shiny uneven spots or drips on the wood. Joann The mantle and the curios are poplar, as well as the stained glass window mantle -- next to the china cabinet. If you want it more reddish add more English Chestnut, if you want it more walnut add more provincial stain.

Your room is very nice. I like the understated combination you have going of browns and whites. Currently, your mantel kind of fades into the brick. I love painted brick and that would make the mantel stand out, but in this case, I like your current brick. Would you consider painting the mantel a soft white or whitewash to emphasize it against the brick and stay with the brown-white combo? I also think a bolder piece of art on the fireplace would bring more life to it and add color.

There is a RustOLeum muted gray spray paint intended for BBQ grills. You might consider painting it with that or a similar product designed to withstand high heat. https://www.walmart.com/ip/Rust-Oleum-Specialty-High-Heat-Ultra-Silver-Spray-Paint-12-oz/196486786?wmlspartner=wlpa&selectedSellerId=2419&adid=22222222227066487799&wl0=&wl1=g&wl2=c&wl3=192936394920&wl4=pla-306315930177&wl5=9011064&wl6=&wl7=&wl8=&wl9=pla&wl10=113134491&wl11=online&wl12=196486786&veh=sem&gclid=EAIaIQobChMI0pqIu6ve5AIVRR6tBh0Oyw_0EAQYBiABEgLbwPD_BwE No fireplace "needs" a mantel if you don't want one; however, if/when you remove it, do expect to find some brackets that were holding it that will need to be removed if you remove the support board, too. You might be able to remove the mantel shelf and its supports and leave the board that is flat against the chimney and, perhaps, cover it with a new fireplace surround or build the surround beneath it and paint that board either the same color as the chimney or the same color as the surround.

Agree that your fireplace, built-ins and wood trim are beautiful. I’d absolutely try to find another place for the TV, and style the built ins with books and a few (ceramic) pieces. (I know many disagree, but a TV screen over a fireplace-especially in an older home- is a hideous abomination to me.) I have a 1914 Craftsman bungalow and am grateful every day to be the owner of an older home. Appreciate your good fortune, and don’t try to turn your home into something it isn’t, please. I would do everything possible before deciding to paint the brick. Ours was painted white before we bought the home, and I so wish it was the beautiful original brick! The white was constantly smoke-stained and ugly, and we ultimately painted the brick a very dark, almost blackish green. We would have tried to restore the original brick, but at the time were not able to tackle that huge and expensive job. We’re not fortunate enough to have built ins like you do. And keep the original knobs, they are wonderful!!