With all due respect to the OP ... the question at hand is not a commemorative related issue but rather a variety/error question.
I have some expertise in the series ... and have avoided replying as I have no expertise in your specific question ... the reason for the various blobs seen in the mint mark.
Suspect our master historian/expert commems might offer a similar reply ... I'll leave that to commems
Take a look at my other hobby ... http://www.finewoodcrafter.com
Too many hobbies .... too much work .... not enough time.