For years I've wondered about this and I still don't have an answer.
In the 2006 illustrated book "Ships of the Line", each era of Star Trek ships is showcased in a chapter featuring pictures and descriptions, mostly vague, of what is happening in the images. The TOS era in this book is referred to as "The Creation of a Legend", and there are three specific images which depict events, possibly non canon, that I have no knowledge of. The first image is a series of Klingon D7 battlecruisers and at least one TOS Constitution-class in the upper atmosphere of a planet, while the description merely says, paraphrased, "if the Klingons attempted orbital bombardment the casualties could reach the billions". The next image depicts a saucer separated TOS Enterprise, with severe damage to both the saucer and the engineering section, as they both target and destroy a Klingon D7 in space. The third image shows the Enterprise being rebuilt, and has a description that says, paraphrased, "The facilities on Bolarus III were primitive, but vital to bringing the Enterprise back from the dead."
Obviously these are events which are not referenced in canon (I've seen every episode of TOS to feature the Klingons and I don't remember anything close to any of these events) but even if they are non canon, I would guess they reference a novel or non-canon work in some way that did feature such scenarios. If anyone has access to the Ships of the Line book or knows what the full in-universe story is behind these images, please let me know. Thanks!
In the 2006 illustrated book "Ships of the Line", each era of Star Trek ships is showcased in a chapter featuring pictures and descriptions, mostly vague, of what is happening in the images. The TOS era in this book is referred to as "The Creation of a Legend", and there are three specific images which depict events, possibly non canon, that I have no knowledge of. The first image is a series of Klingon D7 battlecruisers and at least one TOS Constitution-class in the upper atmosphere of a planet, while the description merely says, paraphrased, "if the Klingons attempted orbital bombardment the casualties could reach the billions". The next image depicts a saucer separated TOS Enterprise, with severe damage to both the saucer and the engineering section, as they both target and destroy a Klingon D7 in space. The third image shows the Enterprise being rebuilt, and has a description that says, paraphrased, "The facilities on Bolarus III were primitive, but vital to bringing the Enterprise back from the dead."
Obviously these are events which are not referenced in canon (I've seen every episode of TOS to feature the Klingons and I don't remember anything close to any of these events) but even if they are non canon, I would guess they reference a novel or non-canon work in some way that did feature such scenarios. If anyone has access to the Ships of the Line book or knows what the full in-universe story is behind these images, please let me know. Thanks!