Believe it or not, even Volvo techs are not 100% sure of that VIN cutoff between early vs late models of the same year as Volvo doesn't make it THAT specific. Usually, the manuals are similar and the late model book is often nothing more than a suppliment to the early model with details on devices or changes that were made mid-year.
It being your money and that you're probably right in assuming that your car is a late '99 model, I'd suggest starting with the later book and see if it's good enough for what you need it for. If it then seems more like a suppliment (not complete), then order the earlier one too.