Lesser Platinum (or just plain Lesser is the name used more now days) is it's own mutation and not a combo. Actually all Lessers are heterozygous for this mutation with one Lesser mutant copy and one normal copy of this white snake gene. But ball python people generally incorrectly only use "het" for recessive mutations. If the het Lesser you saw for sale was normal looking then it doesn't have the Lesser gene at all.
Pinstripe is some sort of dominant but we don't know yet if it's completely dominant or co-dominant. As far as I know there isn't a proven homozygous Pinstripe yet to answer that question. Pinstripe might be like Spider and eventually get to the point where the existence of a proven homozygous is so far over due that it seems doubtful that it's possible. But I don't think Pinstripe is nearly as old a mutation so maybe just not time yet to produce and prove a homozygous Pinstripe.