There is a stamp which says HARRISON F 55.Should there be a seal of some kind between the blower outlet and inlet to the heat exchanger. Few more pics
[IMG]http://i1060.photobucket.com/a...ff/20180110_202146_zpsb6drgwuv.jpg[/IMG]
[IMG]http://i1060.photobucket.com/a...ff/20180110_201858_zpstj0qtp0x.jpg[/IMG]