Help with Elmira Stoveworks insert

You guys have been great with your comments & suggestions.

I am thinking of buying a used Elmira Stoveworks wood insert.
27" w x 22" h x 18" d

The company went out of business about 5 years ago ( the units were sold under the Heartland Stove Brand)
My question, does the flue sit on a flat top or is it angled at 45 degrees.

My current fireplace is only 24 " h & an offset box may not fit from a flat top flue to the damper area for direct connection to the chimney liner.

Thanks
Mark