Removing Heat Tubes in Heatalator Fireplace

I pulled out the old insert today and wonder what to do now. I want to prep the chimney for an SS liner. However, there are three metal tubes to deal with. Here's what I have:
a 1966 era fireplace that measures about 35" at front of opening and 29" at rear.
a metal liner or jacket, but the fireplace floor is brick.
three metal tubes at top of fireplace that vent through brick about halfway between top of fireplace opening and mantle.
he tubes are evenly spaced at about 8, 16 and 24 inches across the opening

I want to get it ready for a freestanding stove install land liner but the tubes prevent access to the rest of the chimney. It doesn't look like I could remove the metal jacket(or heatolator unit) without a major demolish of the fireplace. The tubes must be about 3" id. and look pretty solid.

Also, as I look up into the fireplace opening I see a pretty good size lever, which I assume is the damper control. I can't budge it right yet. However, using a flashlight I can see the opening to the chimney and it doesn't look like there is any damper. In other words, I can see between the tubes and there appears to be nothing above them except the chimney.

Thanks for your replies.

Reed102, when you said the whole thing, do you mean all 3 tubes or the entire metal liner? If I take out just the middle tube will I have enough room to get liner up chimney and then do the block off plate? If a problem then I should take out all three. Right, I don't plan to ever convert back to a straight fireplace so I want to make the (best) changes now.

Elk, short story - BCNU was the name of my father in laws first boat. He took his family on a few trips to Vancouver Is. in the mid 1950's. So it's a bit of a play on words. It's what the boaters would see as he moved on and it also highlighted where he was - British Columbia. He and I went on three trips along the west coast of the Island in the late 80's- so the name serves to remind me of those special times. Dad just turned 90 last week end and he's still in excellent health. Also, I couldn't think of a good fire moniker when I first logged on.

When I look up into the chimney the opening looks huge as it slopes to the rear of the fireplace. Looks like lots of room for liner and I still don't see a damper(maybe I just don't recognize what one looks like). I will also consider cutting the back of the metal fireplace liner to get a straight shot for a ss liner - but it looks like cutting the one tube would be quicker.

Hey Elk, now I have to ask. I assume BC is Boston College but I can't come up with NU. The rivalry sounds a bit like that between we wood stovers. :coolgrin: