In my opinion, given that the scales have that long rounded tapered triangle shape, I think the shield would look good matching this. Note the long and thin shape of the pieces that drape over the thighs. I think a shield with a flat or barely convex top, narrow, then a long, rounded tapering triangle or spearhead shape shield. I say rounded referring to the taper to the bottom point, which I think should be very sharp and angular at the end, not rounded. I dont really see any boss or spike on such a shield, I think a smooth convex surface would best match the scale mail

What im really interested in seeing is where you go with that axe :) Will it be a horsemans weapon to use when mounted upon any number of different fantasy beasts rather than the footmans big double bitted Conan style? I kind of see something long handled with a halbardish head and just barely ornate, but all business, in my minds eye :)

Cant wait to see what you release as time allows!