I don’t know about the first book - but the second sounds a bit like “The Devil’s Guard”, a book by a strangely elusive author named George Robert Elford, and published in 1971. Elford claimed to have based the book on an oral narrative given him by one “Hans Josef Wagemueller” (cover name), a veteran of a Waffen-SS antipartisan unit who, having escaped from Eastern Europe at the end of the war and reached Switzerland, subsequently joined the French Foreign Legion and served in a brigade of ex-German soldiers (the self-styled "Devil’s Brigade) in the French Foreign Legion in what was French Indochina. It is somewhere at the far end of my “should read” list. The book was long out of print, and difficult (and very expensive) to source; more recently, it has been reprinted and is now quite easy to obtain at reasonable prices.
Reading reviews on Amazon, it appears that many people have enjoyed the book on the level of a “ripping yarn”. However, even they often express doubts as to its authenticity; and others regard it as a tedious fiction masquerading as fact. Not having yet read the book myself, I have an open mind (to some extent at least) on the subject. However, from the reviews, the style and content suggest a work that contains a very substantial element of fictional embellishment, and features a level of anachronisms, errors and timeline difficulties much higher that the relatively small number of errors that persuade some to condemn Guy Sajer’s “The Forgotten Soldier” as fiction masquerading as fact. I have read Sajer, and tend to the view that it is largely authentic, albeit marred by several significant errors that may be put down to the fallability of memory. By contrast, “The Devil’s Guard” seems to be closer to Sven Hassel than to Sajer - a work with a very substantial fictional or fictionalised content, perhaps containing some authentic content derived from some (uncertain) source. I will reserve final judgement until I get down to reading it (unlikely to be soon - I am way behind in my reading).
In any case, if this is the book you want, try Amazon. They seem to have a number of copies from recent reprints of “The Devil’s Guard” and its sequels (yes - it has sequels, which do little to promote its credibility). Anyway, a lot of people seem to have enjoyed the read, even if it is only as a yarn. Best regards, JR.