Maybe you can answer this cause honestly I don't know. I agree that there are Christians who heed the likes of Wesley and the Westmister Confession in regards to the Law of God. But I also see a more prevelant Law of Christ 'crowd'. From what I have gathered the Mosaic Law has been rendered done with and we are now under the Law of Christ. Although there a lot of resemblance between the two that doesn't mean the Law of Christ includes any Mosaic Law/s. One big diffidence I can see is that the Law of Christ doesn't include the 4th commandment.
So it a 'you say potatoe I say patatoe' type of thing?
I see it rather more simply than that, brother. Loving one's neighbor fulfills the "Law of Christ", and loving God etc....you know that. To me, the word "Torah" is a loaded term around here, and that loading has made the term meaningless.
When someone who claims to be Jewish tells me that they are "Torah observant Messianics"...I have no idea what they believe, how they live, or what the Torah means to them. It's just a trendy throw-away line to me. The big questions are not addressed in such relative religiosity. Do they visit the sick? Feed the poor? Usually not. Usually they are basically religious in their heads but their hearts and hands are pretty much non-observant.
I know this from experience. As a minister of Jewish background and rearing, a lot (and the number is rising) of people come to me with questions about being Jewish and so forth. I have found that they are prepared to learn about Judaism, the OT feasts etc...but when I invite them to actually live Torah and work at our soup kitchen....they run a mile.
I think Jesus was really on to something in all this. He really does say that the heart of the Torah is love of God and neighbor, and when I see that this heart of the Torah is "too hard" for people wanting to be "Torah observant", I really think all the arguing about which law is done by whom and when etc is a complete waste of time.
What's worse (and now I will vent a little) is that these same kind of characters will then go around judging me as "not observant" or "not Jewish enough" or whatever strange fantasy enters their minds in order to hide their own guilt. The fact is that I own, daily use and treasure tefillin, a tallis or two etc. I study the Shulchan all the time. I read the Talmud. I do my best to attend to Moedim, but that sometimes must be put aside for service to my people and neighbor. I am, in fact, an authentic Messianic Jew. The difference is that I don't need to advertise. I wear my kippa on the inside, where it matters most.
So, when I see Christians teaching the commandments and preaching from the whole counsel of scripture and then going out and feeding the poor and visiting the sick...I agree with Jesus and say "well done thou faithful servant". I don't need to judge their observance of religious rituals or adherence to the feasts given to the Jewish people. That's not my job. I'm here to encourage the same mitzvahs that Jesus did, and I'm not here to make everyone a Jew.
Hope that helps....although I may have missed your question entirely! Sorry in advance.