The laws about open carry are vague for a reason, it creates confusion and allows police to use disturbing the peace charges against you if they wish. If you are in another town, your COP will be notified and he has the option to find you unsuitable. If you've talked to him before hand on the subject, you'll know where you stand and if he will jam you up or not.
You have valid LTC Class A, I recommend going to the Chief who issues that LTC. If they do not have a problem with OC, then you should have no issues. Unfortunately the way MA laws are, they are pretty much the final say on this, unless as stated in the previous post, you go to court and get that nullified.
I know COP's who have no problem with it, but most are in Central/Western MA. And most will tell you they'd rather you conceal, that's really the "intention" of the license. I'm willing to bet 90% of COP's you talk to will say that, to A) not have to deal with other chiefs who might have a problem with it and B) not have to deal with Sally Soccer Mom seeing your gun and calling them.
In the vehicle, a loaded firearm has to be in "direct control". Again....vague and open to interpretation by law enforcement. But I dont think in a holster on your person can be argued against, that's really the best place to carry it in a vehicle. If you are OC'ing in a vehicle, there are no laws against it......however, Soccer mom sitting in traffic on the side of you looks into your car and sees gun on your hip, calls cops gives your license #. You get pulled over and maybe disturbing the peace is charged...maybe not, this all depends on law enforcement.
Like it or not...in the state of MA, your Constitutional rights are tempered by Law Enforcement.....if you choose to do things lawfully.
But the laws are so vague and open to law enforcement interpretation, that they can essentially jam you up for almost anything.
Some people chose to accept it, some choose not to and just do things illegally and never get caught. Right now they are in the process of creating more laws which will make law abiding people into felons by owning magazines they've legally owned for years and making law abiding gun owners carry insurance, one gun a month limits, no personal transfers, etc...
I will leave if these new laws passes. I'm tired of being a subject to this ********.