Good looking hull, I have always liked the shear lines of the Master Angler.
As for access to install cleats that you do not have access to reach behind, you have 2 options that I know of.
1. Use the backing plate if provided or make one and Epoxy the nuts on to it (See photo below). Cut out the hole for the cleat and insert the backing plate using some monofilament to hold it in place. Put the cleat over it and just get the screws started. Trim off the mono and bring the machine screws tight. I have done this and the cleats have been there for years now.
2. This will be some what controversial with some. Ken Doss (Hobo) posted here that he installed many cleats with just drill and taping the holes for machine screws (Typically 10-24 NC machine screws). I assume he used 5200 or 4200 bedding. He said that he never had one fail. If I were to do one again, this is what I would do too.