That baffle plate looks like it has seen plenty of abuse. It's easy keeping the outside like new. The inside tells a different story.
That appears to be a Grandma III from 1979 when the arched top doors were an option that year. The angle iron is put in like factory and the length and baffle plate size with notches is exact. Normally you only see baffles in the III with rounded corners and no angle iron corners. (The UL listed stoves) This was during the '79 to '80 change. The old style like this one was not Listed, but was made in the old style for many years later as a cheaper stove where UL Listing was not required, such as on non-combustible surface of hearth, or on cement floors and near cement walls. After 1979, this would have had arched top doors. The bent handles give it away as one of the later, early style models. Definitely just before the change.
For those that doubt there was a III that co-existed with the new style;
Here is both on the cover with optional arched top doors and Fireplace Legs on the UL Listed style in the front,
and the stove pictured is towards the back. That is the '79 manual.
Here is the baffle plate in my Goldilocks. This is close to the same size stove pictured above. (Grandma) I bought it new in January 1985. The baffle wasn't cleaned. It is just as it was when taken out of service, used as the only heat source for over over 20 years. Rust and warp free, don't know what I did to keep it in such good shape. I even checked it with a straight edge! It is like the day it was put in. With new brick you would never guess it had much use.
The others in my collection are new, unfired. That's "mint".
This is what Mint looks like;
Unfired Papa (before cleaning)
Papa / Mama Door
Grandma III Door
Unfired XL soaking with WD-40 before cleaning. (I use WD-40 in the house due to smell)
The inside after cleaning it up from sitting 40 years. I use Maas metal polish inside that leaves a protective film. It is for precious metals such as gold and silver, but works equally well on steel and gray iron castings. (when you can see yourself looking back at you inside your stove, I think it means you have issues)
XL nickel plated door, inside and out.