Yes, the Salmon Marans popping up is completely and entirely possible. Lucky you!
And yes...sometimes, even though all parent stock have feathered legs, they can produce offspring that are clean legged or sparsely feathered.
What this means is....atleast 2 (possibly more) of the birds in the parent stock (the rooster and 1 or more of the hens), each carry 1 recessive gene for clean shanks and when combined, both contribute their 1 recessive gene to their offspring and 1+1 = 2 copies of the clean shanked gene, therefore the chick will express a clean shank. Hope this helps.