Can I save my Fisher?

A seam across the back on any Fisher is new to me. Normally only the front is made of multiple pieces. If it's a VI, it should have bent corners with no welds except where the wrap around stove body meets. If you have a horizontal seam, you would have vertical seams at the corners as well, since a VI shouldn't have angle iron corners. Perhaps a poor cut of the vent hole on the back necessitated the new back upper section?? It would have been welded, no furnace cement was used. You should grind a V into the seam for best penetration and weld it with whatever you have. A flat plate an inch or two wide across the back covering the seam, then welded would assure the seam stays sealed. Camfan can probably give you more specifics on that. He built many from the Georgia fabricator. Your tag should tell you where yours is from. Does it give the fabricator name?? I'd like to see pictures of the outside of your stove and a close up of that tag.
Somethings Fishy at the Fisher plant when you have to Fish-plate that stove. :coolsmirk:

Not sure what you mean by "the cap on the back flue". Does this stove have a top and rear vent? Or is there a cap on a pipe T? Pictures of that would be needed as well.
Did you get the date and model from the UL tag? 1980 would be one of the first of that model made too.

Thanks for the pictures. Can't tell you why it has both rear and top outlets, or why it was made with a two piece back. There were barometric stoves with two collars, but your inside picture doesn't show the box that would cover the rear vent hole. A barometric damper was installed in the rear hole as an intake up the stack. 2 pictures of the barometric air box below.
Hesston was the largest fabricator. I don't know if they would special build one for someone ordering one with the option to vent top or rear. If so, they would have used a top with the vent, and a back with the vent on one stove. I don't see a need to cut it across the back.

It's definitely a transition stove going from the old pre 1980 box with welded angle iron corners to the new wrap around with bent corners and bolt on legs. Most VI models look like the Mama pictured below; Notice the seamless corners.

I just noticed the seam is about the same height as the rear shield. Does the lower rear wall plate measure the same size as the shield? Could they have screwed up and cut the rear sheet to the size of the shield? Then extended it? It's certainly one of the first VI's made with the old box style.

If you haven't read the Fisher Stove Story, check it out. Hesston Corp. is mentioned and is the big manufacturer that required a $750,000 guarantee from Bob to retool their factory to make his stoves if they didn't make as many as he claimed. Fabricators across the country were 20,000 stoves behind, and this is the company that could make them for distributors and catch up. This contract signing is also where he had his stroke. A little known fact is when he was the last to sign the contract, it was passed to him, and as he pulled his pen out of his pocket and signed, the pen point wasn't clicked out. He was too embarrassed to resign it, so folded it in half, threw it on the table and said "you've got a deal". They made far more than anticipated on the contract, and the signature went unnoticed.

The door certainly is not from a Papa VI. (They used the same door as pictured above on Mama VI) It is a pre-1980 stove body and door; (with older 4 fin dampers at that) With the lower back, shield and tag from a 1980. It could have been during the transition from flat to arch top door, there were a few UL listed new style boxes with old doors. And quite a few old style boxes with new arched top doors in the double door stoves. Apparently fabricators had the old style boxes made up, and started getting the new doors for 1980 and used them.
If done by the fabricator, the seam would have more than likely been welded correctly.
Looks like you've got a little '79, a little 1980, a little top vent, and a little rear vent going on. It's unique. Never a dull moment at the Fisher factory. Those were hectic times.

With the second course of brick, you can easily lay a piece of 5/16 steel plate on top at the rear as a baffle under the top vent hole. A 1 3/4" (or 2 inch) slot all the way across the stove right about at the bend in the top is equal to the cross sectional vent area of your outlet. The more you make the rising heat change directions in the upper chamber the better. You'll see a drastic reduction in smoke and a hotter stove than the pipe ! I'm on a Baffle Crusade. It's all good.

The door was open and closed against the latch. Look at the sideview picture to the right. The handle is up where it should be. Don't ya hate it when handles go limp?? Or you open a door and it drops an inch ! I had a truck like that......