Every question that starts out with "Is it illegal [or legal]..." requires an answer that starts with, "That depends."
So hear goes:
That depends.
Where do you live?
Where do you want to carry?
What credentials do you have?
How old are you?
Are you a criminal?
Are you crazy?
And it goes on and on.
The biggest caution is don't do ANYTHING on the advice from some Bozo on the Internet.
That includes me! I am a BOTI as far as you [or the courts or law enforcement] are concerned.
Mistakes in your area of concern can be painfully expensive.
Here is my advice to get the information you need:
Get guidance from people that are trained and experienced it the area of your question.
Start with a lawyer... this IS a legal question, right?
Get someone who is knows the field. You should be able to mention BATF, GCA68, NFA34, Class 3, SOT, SBR, AOW and the lawyer should know what all of that stuff means without having to check a computer or book.
When you get the advice you thinks guides you correctly write a letter to whatever legal expert you use with a set of explicit questions. Like "Is it legal for me to... carry... such and such... at... blah... blah? Then get written responses and justifications that you understand. Keep copies around. You may need that later. [Actually the rule is: If you have the copies you won't ever need them. If you don't have them... well you get the idea.]
I have written state AGs with specific questions. In your case you might want to add some federal offices since jurisdiction over you actions are covered at multiple legal levels.
I'll pass along this caution. I once thought it would be a good idea to get guidance from BATFE about something. I got this advice from my law enforcement mentor [FFL/Class 3] when I asked him how to approach the concern. His advice to me was NEVER CONTACT BATF about this stuff. You don't ever want them to start sniffing around in your gun business if you can help it. Get advice from the most knowledgeable people you can tap.
So
@Hog Doc , I can't give you any specific advice. But I am surely interested in you journey thru this. Please share what you can with us about your journey about this.