Mmm, maybe not. Here's how I understand the process:
Center RT with blank; lock the Y axis. Adjust boring head to appropriate radius.
Move the X-axis until the boring head just makes contact with the blank. Raise the boring head, move the X-axis another .010" or .020" (or however much you want to take off each time) and "bore" down the blank (actually, the inverse of a bore since you are cutting the outside). This will shave a little off the flank, but not yet down to the base circle. Move the X-axis another .010" or .020" and "bore" again. Repeat until your X-axis setting is at the point that the boring head is cutting the blank right up to the base circle. Now lock your X-axis. NOW you rotate the RT a couple of degrees, and "bore" again, and repeat until the full shape is reached - you don't have to work your way down to the base circle after the first time, because only a little bit has to be cut with each couple of degrees of rotation.
From your description, I'm wondering if you skipped the part in red above - went straight to where the boring head would cut right up to the base circle, and "bored" down. If so, you would have been taking off a rather big bite on that boring pass. After that, as noted above, when you were at the base circle and turning the RT a couple of degrees each time, you were only taking a small "bite" each time.
Again, even if you skipped the part in red, you succeeded and nothing broke, so no harm done. If your mill and boring head can handle that big a bite in one go, it certainly would save time!
On your last question, it sounds like you are deciding how far around to go with the RT based on the nose radius. I can see that this is the way the plans are written, but I would say ultimately it is not the best approach. What you really want to do is to figure out how long (how many degrees of camshaft rotation) you want the valve to be lifted, and by how much. That said, let me see if I can reverse-engineer what you've got on the drawings. Here's a diagram that reflects the known parameters from the drawing - base circle is .334"; the blank is cut to .480"; the nose radius is .025"; and the flanks are cut using a jig with a .958" cutting diameter. The heavier cyan line shows the cam that results from these parameters:
Now we can work out the resulting angle of duration and the lift. Presuming that the blank (diameter = .480") is to represent the outermost part of the cam, the lift can be calculated as the difference between the base circle radius and the radius of the blank: (.480-.334)/2 = .073" of lift. With the help of a CAD package, we can easily find the lines that are perpendicular to the point where the flank circles are tangent with the base circle - or to say it another way, the point at which the shape starts to follow the flank outline rather than the base circle outline. Furthermore, the CAD package lets us measure the angle between these lines:
So, if all of my assumptions are correct (probably a dangerous assumption in and of itself!), then the duration of the resulting cam will be 124.42°. Let's round it up to 125° just to make life easier. This will let you set the valve timing for something like opening 20° BTDC and closing 15° ATDC, which seems reasonable based on my limited knowledge and experience.
But here's the key thing: the best way to cut this is not to keep on rotating the RT until you can fit the .025" radius gauge; rather it is to rotate the RT the desired amount to achieve the 125° of lift duration. So, 360° - 125° = 235°; if you rotate the RT a total of 235° (a couple of degrees at a time, "boring" after each turn), then the resulting cam will be correct, and you will only need to file the nose round (IOW, smooth out the transition around the nose) and smooth any slight irregularities around the rest of the cam introduced by the steps in cutting.
Clear as mud?!?
