Yes, there are many manuf of gas fireplaces. Try Heat & Glo for one. It is un likely that the masonry chimney is functional. That old a chimney will not have a liner and being so old is probably the reason it was originally modified. You could call a chimney sweep, but make sure it is a Sweep Certified by the Ch Sweep Guild. Otherwise go to a local Hearth shop to get some ideas. Take some photos to help them advise.

It had a small stove for winter that was removed in summer.

Making it "functional" ... you need to make sure the chimney is sound, then decide what replacement stove you want. Or install a really shallow gas or electric faux fireplace with the appropriate venting.

What looks like ground soil is almost certainly granular creosote fom wood or possibly coal burning. There should be a cleanout door at the base of the chimney where you can remove the accumulated material.

No matter what you decide to do, the first step would be to have the chimney cleaned and inspected. Liners can be added to old chimneys. Some are stainless steel, others are cast in place. The issue is complicated in your case because the photo shows flammable vertical framing members right up against the chimney on both sides. This would be a violation of present day building codes for solid fuel chimneys, I'm not sure about gas appliances. Then there's the electrical line and the lathing...

Another reason for inspection - preferably one that uses a camera - is to check that there are no other openings to the chimney on the second floor if the chimney is currently covered. People frequently put cast iron covers over the openings, then built over them just as you have on the first floor. This is very dangerous. The iron covers can rust over time and fail, even drop out of the opening altogether, creating a very serious fire hazard and a path for CO to enter the living space.

Thanks for the responses. Can anyone tell me what this likely looked like originally? Would that mantel have been there with the small stove in front of it?

I have the same mantel in two other rooms of the house.

And just to be clear. I have no plans to use the chimney other than to run air tubes for a direct vent stove of some kind.

I doubt that mantle was added, especially if you have others that match.

Just for kicks, strip off a bit of paint. You may find some quartersawn oak, you may find it was originally painted.

My house was renovated in 1906 with similar brick chimneys and mantels placed as "corner" fireplaces (and presumably coal stoves) which replaced the stone end-chimneys with wood-burning fireplaces, which obviously would have been way cooler, had they survived.

This post was edited by sombreuil_mongrel on Mon, Aug 18, 14 at 14:23

We had a similar situation of a bricked up opening for an old stove with an unsafe chimney, but in our case there was another similar opening for a stove in the room behind it. (Our house was built in the 1860's.) We ended up taking out the old chimney and all the stove openings that fed into it (4 total) and rebuilding the chimney with a Rumford (shallow) fireplace that faced into the living room and just a sheetrock panel in the bedroom behind it with the mantels intact.

Here's the opening with the masons getting ready to start the fireplace with the masonry support for the chimney rebuilt from the cellar to the first floor, looking from the bedroom into the living room.

This post was edited by nhbabs on Mon, Aug 18, 14 at 21:29

And here just finishing up the firebox on the living room side. The mantel in the bedroom was taken out temporarily, but was replaced after the chimney and fireplace were rebuilt.

If you don't want to go to the expense of re-building a chimney/firebox, you can add a gas freestanding fireplace. We have an insert by this company (Valor - in the link) but almost all the work was taken care of by the company who installed it. They can out to inspect the chimney, took out an old liner, put in a new one, capped it, ran gas extension lines and installed the unit itself. They are pretty historically correct and cast iron.

Here is a link that might be useful: Valor fireplaces