Recently i had darshan of Alampur Jogulamba. I could not see the Bhudevi in Bala brahmeswara temple as priest shooed away men as women were doing some Puja at that time. Later i visited the museum and after coming back read the full information in this site. Below are few of my thoughts.
There is another idol of Bhudevi in museum and below is it's photograph.
It was written as 'Nagnakka Banda' in telugu - translated as 'Stone of the Naked Sister'. Therefore i guess the other idol was misspelled as Narmakka Banda.
A few months back i visited Badami and in Badami museum also there's a sculpture like this and it's called ' Lajja Gauri' - the worship of fertility goddess. Also i would like to say that the Nava Brahma temples of Alampur are almost similar to the temples in Aihole. The common thing in both the temple architectures and Lajja Gauri is the Chalukyas i believe.
Also i came across this link (http://shaktisadhana.50megs.com/Newhomepage/shakti/lajjahGauri.html) which relates Lajja Gauri worship all the way to Aditi of Rigveda and even to proto-Aditi of Indus Valley. And as mentioned in this link the sculpture in Badami museum is the most beautiful of the three. May be many of you are already aware of this, but thought useful for someone new exploring this place.