Fisher XL Questions

Welcome to the Forum!
1) Yes, they are harder to find, production started in 1978 with a limited customer base needing such a large stove. The "Sun" door was a part of the solar business they were getting into. The common Fir Tree doors were also used. Both are rare, and I've only seen rear vented "Sun" models.
2 & 3) The second row of bricks started in Mama and Papa Bears in July 1977 giving them the Roman Numeral II designation. Many fabricators stuck with the angle iron brick clips with only one course of brick. There have not been enough XL's to surface to make a determination on how many were made with or without the second course. My new in box XL has this second course, rear vent, Sun doors. Other Sun door types found have had this second course. Below is the inside of an XL from eBay, Utah a couple months ago that shows one course and a baffle. This is a Fir Tree door stove. Sun doors, so far have not had the baffle, and have had the second brick course.
The second brick course does not effect Mama and Papa when not present, and their sides are larger and more susceptible to warping. So I wouldn't be too concerned.
4) You're correct on all accounts; Reduction is not allowed technically by codes, but many do and will work. Baffled Grandma and Grandpa were the III model and did not use a damper. Before the baffle existed, in the first owners manual a baffle was recommended. So I would guess a damper should be used without a smoke shelf baffle, and not necessary when the stove has a baffle. Personally, I use one either way.

The absolute best way to heat your area with a Fisher, is a Papa Bear with 6 inch liner. Nothing like the advantage of 30" wood, small pipe and a huge cooking surface. The only disadvantage is not being able to view the fire. (which you need a screen for as well)
With your current 8 inch chimney, a Grandpa is the correct size for the home.
If you're a Tim Allen kind of guy, you're going to love your new XL !

If this is a Sun door, it should have a stainless tag on the left rear leg with serial number and state initials where it was made.

Notice the factory baffles normally have the notched corners. This is an indication of factory or not.
I'm close to finding out the model designation between door models given in prints and ads.
Here is the oldest ad I have found for the model in Feb. 1978.
http://news.google.com/newspapers?i...AAAIBAJ&pg=5472,3966402&dq=fisher stove&hl=en

What intrigues me about the XL is how far ahead of it's time it was. It's like it had another engineer or designer when all the Fishers being made at that time had flat top doors, block letters across the top of the door, and angle iron corner legs. The "pre 1980 look". Many old style boxes with angle iron corners exist with the new arched doors during the '79 -'80 transition. So in Feb. '78 it would make sense that the new XL model would have had angle iron corners, and flat top doors, just being made larger than a Grandpa. But that wasn't the case. Along comes this totally different beast. Box, legs, and round top doors. I'm thinking the Sun doors were part of this total redesign. They would have been the first arched top doors on a Fisher. This was the first with bent corners instead of welded corners having angle iron corner legs. So the "Sun" XL existed 2 years before the changes were made to the rest of the stoves in 1980 ! The arched doors with trees and baffle started in the 1980 stoves. I notice the ad I posted states the Sun style came with a damper. Verifying the older XL with the Sun didn't have a baffle.
I found the first use of the arched door with trees in an ad dated Dec. '79 on an Insert when all other stoves shown in the ad were still the old style door. http://news.google.com/newspapers?i...AAAIBAJ&pg=1605,1850748&dq=fisher stove&hl=en
May be able to date yours if your doors have some markings inside like the GM and GP. Camfan on the forum, mentioned in a phone conversation that he saw a set of prints labeled I believe 300XL (?) dated before prints showing XL only. That may be the door difference.