Joan Grant was an author of historical novels about ancient Egypt including "Winged Pharaoh", which were in fact based on far memory. In this book, she writes candidly about her own experiences and understanding of reincarnation. She alternates chapters with her husband, psychiatrist Denys Kelsey. Although this book is very readable, with numerous personal examples and cases, it presents some advanced concepts in reincarnation studies that you don't see elsewhere. In particular, the couple discuss with authority the entire cycle of reincarnation, including the "re-entry" process and aspects of how the new person, and the new body, is formed. She also goes into details about her own childhood awareness, and by inference, the unimagined degree of awareness that young children have. I think this book and the advanced concepts it puts forth will be rediscovered in reincarnation circles as that field matures.
There is one caveat I'd like to add. Joan considered herself psychic, and from her biographical accounts I think it's likely she was. Nonetheless, her technique for retrieving "far memories" had to do with catching a glimpse--such as many people have from time to time--and "following" it, i.e., trying to get more out of it. (This was the beginning--later on she describes her technique as "shifting" to another state of consciousness.) From my own experience and from reports of other people who have tried this, I've concluded the results are easily tinged with imagination. Many people (including myself) report being unable to "extend" their memories past the initial glimpses at all--and in my observation, those people who claim to be doing so are often unable to verify the "extended" aspects historically. I suspect it is precisely these "extended" aspects--sometimes drawn out of a person by well-meaning investigators--which may prove to be historically incorrect. This phenomenon casts a shadow of doubt over the reliability of past-life memory altogether. However, I don't think it's warranted to throw the baby out with the bathwater, because the research clearly shows that past-life memory can be historically accurate, and hence is a real phenomenon. For this reason I feel it's best to rely on the initial glimpses themselves, making inferences from patterns that emerge from these more reliable core memories. At the very least, some effort should be made to distinguish the core memories from the "stretched" memories.
What I'm implying about Joan Grant's work is that it's possible that despite being psychic, her far memory was not entirely free of imagination when she employed this "stretching" technique, and that she quite sincerely underestimated this effect. If this were true--and I'm only suggesting it's a possibility--it wouldn't invalidate her core memories, nor her advanced understanding of the principles of reincarnation.