Thanks to the wonderful world of online shopping, I now possess all four of Martin Caidin's Cyborg novels: Cyborg, Operation Nuke, High Crystal and the imaginatively-titled Cyborg IV, which is also #6 in the Six Million Dollar Man series of novels. Say what?? Yes, it's confusing, but at the same time Caidin was writing his Cyborg novels, other authors were penning adaptations of the television show adapted from the original book. The non-Caidin titles were cycled in with the canonical Caidin works, which is why you have the odd situation above.
In any event, I've already read the first three and I'm looking forward to Cyborg IV, definitely the most elusive and expensive of these long-out-of-print pulp confections.