Hello,
I too am descended from the immigrant Thomas Holcombe (my 8th great grandfather). I have long pondered the question of his parentage and the issue of Gilbert's having been listed as dying dsp in the Visitation of Devon. Although in the absence of proof, we must assume Gilbert isn't Thomas's father, there are some lingering, and very odd questions which remain concerning the oddities found within the notation in the JL Vivian's Visitation of Devon regarding Gilbert Holcombe and Anne Courtenay. Gilbert doesn't appear to have had any sisters, so who was his "brother in law" Richard Bonithon? Gilbert's will was probated in about 1623/4 and yet wasn't dispersed and completed in terms of goods distributed until decades later (a very long time, was the will disputed, and if so, by whom?) when Richard Bonithon's nephew was given rights because Richard had died by then. Perhaps Richard Bonithon was a brother in law of Anne De Courtenay's (husband to one of her sisters?), but this is an unlikely heir given that Gilbert must have had nephews and nieces from his two brothers Josiah and Christopher upon which he could have easily bestowed his entire estate if he had no natural heirs and wife. Richard Bonithon can't have been Gilbert's brother in law because the pedigree lists no sisters of Gilbert's, unless they were left off for some reason. Also, when did Anne Holcombe (Courtenay) die? I haven't found a solid date, only "abt" 1642 or so. If this is correct, that means she died after her husband, but wasn't the legatee of his will. That's odd in and of itself. Perhaps she was already gone when Gilbert died in 1623 but if she wasn't dead yet, why didn't she inherit his estate? Thomas Holcombe was born in or around 1605-1609 so by 1623 he would have been 14-18 and old enough to leave home if he chose. He could have easily left for Leiden Holland with separatists and never been heard from again, after that, sailing to America. Perhaps Gilbert and Anne had several children, some who died and some who left the country or were disinherited for reasons unknown to us. Was Anne herself disinherited? Gilbert Holcombe was a gentleman and so could have afforded to legally seek a divorce from Parliament if he wanted rid of his wife for something like adultery, etc.....If there was adultery, he could have certainly disinherited her, and any children they had together. Perhaps Anne abandoned Gilbert, or perhaps a family rift of some kind caused Gilbert to disown everyone and give his money and estate to a distant relative out of spite. The questions are lingering and endless, because there is no clear answer as to whether he never actually had children, or just died without "legal" heirs, thus the "dsp" notation. Again, it's odd that a man with two brothers would bestow his estate upon someone other than one of those two brothers, or, their children if they had both passed before Gilbert.
I don't think it's wishful thinking to examine some of these strange "stand out" issues, none of which are elaborated upon by JL. Vivian in his pedigree Visitation of Devon (or Cornwall). Therein lies the problem with straight pedigree charts such as those found in that book. They never give any details nor legal explanations as to why something occurred, leaving the researcher to wonder as to what story lies behind the pedigree. Although dsp typically denotes dying without issue, it could also have been a notation which merely outlined that no issue or heirs of offspring were mentioned in his will, which btw was oral, not written.
Food for thought. I hope someday someone finds Thomas's parents, because no matter who they were, they mattered.