Hello all,, I pulled the sheet metal fireplace out of a zero container. I'd like to put a Buck #74 back in. Do any of you see a problem with this? Clearences around the unit are great that it can be walked around. everything from the zero is still there except the firebox. The old unit was for looks only. Very little heat. Every thing went straight up the flue. And if some body knows= what is the differance between zero insert vs regular insert and mobile home certified vs manufactured home certified inserts.