Lets start out with some elementary genetics definitions, provided by www.dictionary.com:
A) Phenotype: phe·no·type
1) The observable physical or biochemical characteristics of an organism, as determined by both genetic makeup and environmental influences.
2) The expression of a specific trait, such as stature or blood type, based on genetic and environmental influences.
3) An individual or group of organisms exhibiting a particular phenotype.
B) Genotype: gen·o·type
1) The genetic makeup, as distinguished from the physical appearance, of an organism or a group of organisms.
2) The combination of alleles located on homologous chromosomes that determines a specific characteristic or trait.
Ok, so now that is out of the way, lets disect this argument further. Firstly you say that a Mojave was produced from a Lesser Platinum(not a Mojave X Lesser Lucy). Well, you are wrong in the generally accepted terms, since most people are referring to the GENOTYPE of the animal, since PHENOTYPES are not inherently inheritable, but GENOTYPES are.
So basically, what you were saying, is that a Lesser Platinum produced an offspring with the PHENOTYPE of Mojave, that most likely had a GENOTYPE of Lesser.
Now, it would be completely shady and underhanded to represent that animal(the one with phenotype Mojave, genotype unknown)as a Mojave, since it shares no common ancestral lineage with the established Mojaves in captivity. There is a very very very small chance that during replication, mutation occurred resulting in a true Mojave, with a genotype of Mojave, but this is highly improbable, as in 1:1000000 or higher.
Another thing that you have wrong is this, even if there was a African "Lesser" imported, representing this line as a "Lesser Platinum" would be incorrect, since they are from a different originating line than the one sired by Platty Daddy. The problem would be this, if you call it a Lesser, then it would be assumed that the genetics needed to produce a Platty Daddy(dilute gene?) would be definitely missing, rather than passed on down the line.
The correct way to market such a snake as an imported animal with a Lesser PHENOTYPE would be to give it a different distinguishing name, either very similar or not. Good examples of this are the different axanthic lines(vpi/tsk/etc), the Fire Balls (unproven line is being referred to correctly as "Ember"
, etc.
Hope this helps, and hope that this cleared up confusion!
-Dan