Hinkles are extremely weight sensitive. The concern with epoxying a Hinkle is the textured scale surface will trap E-tex in the scale pattern and add too much weight. I make a similar size glide and when I dip each half in KBS clear, it adds approx 1 gram of weight to each section of the bait for each dip, and my baits are smooth sided. Couple extra grams and the bait won't swim right. On one of my glides, the difference between slow and fast sink is about a gram. I would spray it with a couple light coats of a sprayable clear so you don't add too much weight. You don't want a bottom rocket. Foil could be problematic because the bait is not flat but has texture, getting a large amount of foil to stick could be hard. You may be able to get foil to stick to the flat, back edges of the scales.
Never heard of holo mist, some pearl paint or iridescent highlights would be nice, maybe lay some color shift paint over the dark back of the bait. IMHO, Hinkles drawing power is not as much the paint, but the glide and the amount of water it moves. Andrew has always had kind of a subdued paint job compared to many other makers.
I believe to take the bait apart, carefully remove the dorsal fin or peel back the front of the fin. You may have to cut it out with a razor knife. There should be a hinge pin under the fin, if you can get the pin out the bait will come apart. Try not to tear up the fin, although I have seen fin kits avail. If you can't get the bait apart, would def use a spray clear, don't want any epoxy in the joint. Hope this helps and good luck, Hinkles are awesome baits!!