Carbenez, I agree with Fred Johnson's Steps 0 through 3. If the SM wants a call, your son can give him a call, even though "by the book" that should not be necessary (more on that below.) Hopefully that will get the job done. If not, I would then follow Stosh's advice (did I say that?) and sit down with the SM over a cup of coffee or other suitable beverage and figure out what the problem is. If its a matter of the guy being overwhelmed with the new job, and you are not already a registered leader, perhaps you want to volunteer to become one and help him out. I am not suggesting a quid pro quo here, but maybe there is some mutual benefit possible here.
I am guessing that when you refer to "a highlighted copy of the Guide to Advancement", you mean the sentence in the section on BOR's that says "Scoutmasters... do not have the authority to expect a boy to request or organize one, or to "defer" him, or (other stuff not applicable here)" So technically a Scout does not have to "request" a BOR from the Scoutmaster, but in practice there does need to be a discussion of SCHEDULING the BOR after the SMC is signed off (or other final requirement, if the SMC is not the last one, but in our troop the SMC is always the final requirement to be signed off, and nobody has ever challenged that.) I am the Advancement Chair in our troop and I do the scheduling of BOR's. Before I can schedule a BOR, SOMEONE needs to tell me that the Scout is ready for a BOR. Sometimes the SM tells me, sometimes the SM sends the Scout to tell me, and if I am not there, they will tell the former Advancement Chair who is now the CC. One or both of us is present at virtually every troop meeting, and if not, my email address is posted in our equipment room. (The BOR will be scheduled for either the next troop meeting or the one after that, though we have been known to do the BOR on the same night as the SMC if enough committee members are hanging around and the Scout wants to do it right then. Or the Scout, SM and I can have a conversation at a meeting in which we schedule both the SMC and the BOR for the following meeting.)
My point is, the SM doesn't necessarily even need to talk to me to get a BOR set up, because the Scout can deal with me directly. If, in your troop, the SM becomes a "bottleneck" to the scheduling of a BOR, that's not supposed to happen and maybe you do need to show up with your highlighted GTA, after you try a cup of coffee first.