I've come across the same country, with the same situation of no help, just don't know if this is the same poster or not.
The main question is where is the bone in this foot? This is my really rough rendition. The name of the game is to, in the end, get the capsule tight to bone. Whether the soft tissue lets you, is another story.
I believe the reason that Mark said don't trim, is because of where the lowest part of the bone is in the hoof. This low area of concern is the blue bracketed area. The yellow lines shows how much closer to the ground the bone will be when the shoe comes off. This area needs to grow higher to keep the bone as high as possible and preserve it....hence why the blue lines run right off the picture.
This is the area where the pressure happens. Its not just pressure on the outside of the sole from the ground, but also pressure to the inside of the sole from the bone itself. Add the two together, you've got periosteal reaction that eats the bone away, and starves the circumflex artery from blood flow. Hence poor circulation and is probably a good part of the reason that the hoof wall looks so unhealthy. Minerals, particularly copper and zinc are also yelling at me. There is notable copper deficiency going on with this whole horse. I can feel it and I don't have a body pic.
The lack of circulation + the shoe is why this horse appears sound. He's not. When the shoe comes off, the circulation will start coming back and pain with it. There needs to be some serious padding on hand to go on immediately after the shoe is pulled. 3" thick styrofoam, for starters. The level of comfort with the padding must be equal to the comfort he has now with shoes on. He must be comfortable to move correctly to promote and be willing to move/eating well. The healing does not begin until the shoes come off. There is just not enough farrier support to justify shoes here.
You want a job done right, you'll have to pick up a rasp yourself, eventually. With no rasping needed right away, its time to learn, cause you're in a situation where you have no choice. Also involved is serious homework with thrush, booting, nutrition, movement and staying on top of the trim.
I'm pretty sure the bone in his foot is not as healthy as the one I've imposed on this pic. There will be soft tissue damage that the xrays won't show either.
Definitely a strict diet, though. I'd feed him minerals instead of free choice with a flavouring to get it down and make sure he got them. Copper is key for hoof health, fights iron and will bring out his true color, but ofcourse, tastes bad. Call the vet and ask him what your area is famous for being deficient in...selenium is a biggie as well.
Good advice....pull the shoes, take pics, pad with styrofoam held on by vet wrap or size 2 diaper and with a duct tape sole, then post the pics. You are not alone.