Yes Brad,
Heco made Hangers as well as Nissen Huts. I have a catalogue with the prices and a photograph of the Heco Hanger (which has opening doors, skylights, and all kinds of interior detail), as well as some additional hard copy photographs of the hanger I received from Tony Williams through our good friend Clive Gande. I also have hard copy photos of a WWI Royal Air Corps Mechanic's workshop, a Radar Station, a Royal Army Medical Corps Field Hospital (two different large brick fronted nissen huts connected to make an L-shaped Hospital building, with a garden, benches to sit on, and a sign reading "Queen Victoria Hospital"), a Canteen, a cookhouse and a small field workshop, and a Barage Baloon Hanger. There are at least a dozen different Nissen huts, some of which have Brick facades and ribbed tin tops. The photos show that each one was unique, with little details like a bicycle left against the wall on some, or sign boards with notes posted on them on others. There is even a Homeguard Nissen Hut which comes with a few Homeguard figures drilling out front.
If your question is whether the nissen hut and RAF Mark III Water Tower I am getting from Marc are Heco, the answer is yes. Upon receiving them later this week, I will have two different Heco standard Nissen Huts, a Heco Wind Sock Tower and a Heco Water Tower.
I would like to get one of the Heco Hangers, more of the different Nissen Huts (especially one with the Brick Facade), and I would love to find one of the Field Hospitals.