I'll look again for that 'other' screw, but I think I have all of them removed.
Thanks for the information, it looks just like what I'm working with. (figure 1)
I'm wondering if the exhaust port of the heat exchanger isn't rusted onto the exhaust tube that extends to the exterior. I'm assuming it's simply flared to slip over the exhaust port of the heat exchanger. (I've even looked from the exterior vent to see if there was some phantom screw there because it feels that way)
I've soaked the inside of the exterior vent tube with penetrating oil in efforts to free it.
(I KNOW, I know... I'll be sure to be VERY careful when I get this thing to fire up, with a buddy, who's versed in extinguisher use.)
I'll be back at it tomorrow or Saturday; let you know how it goes...
Thanks again.
