Can you ID a het visually?

Correct. With a co-dominant mutation the heterozygous animals are visual mutants. If you breed a pastel (which is a het even though most don't call it that) to a normal the normal babies are completely normal for pastel, and the pastel babies are the hets. It's because the homozygous pastels (aka super pastel) are a different visual mutation that this mutation is considered co-dominant.

It looks like pinstripe might be the first proven dominant mutation with visual mutant hets that look the same as the homozygous mutants. So from pinstripe X pinstripe you would have normals and 33% chance homozygous pins.

With recessives you aren't supposed to be able to see the hets, only the homozygous versions. That's part of the definition of recessive. But it's looking like there are some recessive mutations where at least occasionally you can see some effect of the single mutant allele in the hets. Maybe a few of the mutations we consider recessive aren't technically text book recessive after all. Sort of part way between recessive and co-dominant.