Bricks, Masonry, Asphalt and Concrete - Stone facing a cinder block porch

I have a rather ambitious project for this summer. My wife wants me to stone face the front porch (cinder block) of our cabin using natural stones picked from the river behind us. So I repointed all of the bad mortar joints, repaired the cracked blocks and reinforced questionable areas with rebar and concrete.

Here's where it gets tricky. There's a one inch gap ( maybe a little more) between the wood framing of the window and the old cinder block. Before attempting the stone facing should I pack these gaps with sand mix concrete? Or should I just foam these gaps, install brick molding and run the stone up against the brick molding?

Also, I'm told that I won't need to put up wire mesh because the cinder block is rough enough and porous enough for the mortar to adhere properly. But an old mason I spoke to recommended that I use the wire mesh as a precaution because the cinder block isn't as trustworthy as modern concrete block. I used his recommendation to do a little bit of stone facing on the back of the cabin 3 years ago and haven't had any signs of cracking. Is this overkill? One concern I have is that the block work was done rather poorly. I don't think the guys who built the place owned a piece of string or a level. So there may be areas where the mortar coating could get kind of thick. How thick? I don't know yet. But any thoughts on the matter would be greatly appreciated. I want to do this once and hopefully never have to mess with it again.

Thanks,

HarryMc