I'm doing a job right now and have done other's were I'm toothing out the brick that had been cut for an opening an filling it in with brick. I take an old brick to the brick yard near me an have them match it.

If it were me, I'd be contacting a local fireplace expert to come look at it. Given the previous owners hack jobs on this wall, I'd be concerned he didn't muck up that fireplace. Being the fireplace is the place for fire, and fire is bad in the house, it's not a place you want to take a chance on. Most real wood fireplaces have stone or brick surrounds. I'm assuming some of that is to displace the intense heat of the flume, but they also serve to help store and radiate heat since most real wood fireplaces are so inefficient. There may also be codes around it, but I don't have knowledge of that. If you were to put a gas insert fireplace in there, that would change things, but again, the expert I mentioned above would be your best resource.

Here's the link: https://www.progressive.com/lifelanes/household/painting-brick/ To be clear and so we're all speaking in proper context, the 3 to 5 year recommendation is about REGULAR HOUSE PAINT. Which I have repeatedly stated that regular house paint is not the best product to use to change the color of brick. 30 years ago there wasn't the range of product to choose from like we have in 2019. Also, from the same article. And, again, to ensure everyone has proper context... "The Brick Industry Association also advises using a porous paint for exterior brick walls, so the brick can breathe." " Zumeta recommends looking into having your brick professionally stained, rather than painted. Although it can be more expensive, a brick stain penetrates the pores of the brick, unlike paint, which simply sits on the surface. It creates new color without some of the long-term risks that come with paint." In addition, the article speaks to the substrate. Which I also mentioned earlier in the thread because it matters. Bottom line is it's not okay to make sweeping, generalizing, fear-mongering comments about the pitfalls of painting brick without specifying product and substrate. The details matter. Lastly, from the article, this is bad advice. Which makes me question the article overall. I wouldn't use Super Paint exterior on normal substrates let alone brick unless the budget was Super tight for painting normal exterior substrates. JMHO: “Choosing a high-quality paint is vital for painting brick successfully,” says Watson. Both Watson and Crocker recommend using specific masonry paint products for painting brick, starting out with a conditioner and a primer, and then using a breathable latex exterior or interior paint, like Sherwin-Williams’ SuperPaint Acrylic Latex."

If this is a pre-fabricated fireplace you can remove everything.