Orbital scale configuration in subspecies of P. molurus is a very valid marker for identification purposes within this complex. If Wagner’s apparent bivittatus did have supralabial scales in contact with the orbit as you stated, this animal would either need to be a P. molurus molurus, an intergrade, or have an extremely aberrant scalation for a bivittatus. I have been around and worked with hundreds of bivittatus for over 30 years and have never seen one where the orbit was not separated from the supralabials by subocular scales.
I have not seen any references in the scientific literature that note any specimen of bivittatus that lacks subocular scales. CITES officers and customs agents in all countries involved use this as their one major identifying marker because it has shown to be the most reliable distinguishing characteristic between the two subspecies. I have spoken with several staff members over the years at the Office of Management Authority in Washington DC and they have confirmed this. The only drawback with this method is distinguishing molurus molurus of mainland origin from those of Sri Lanka origin. This is why CITES considers these two as identical for enforcement purposes and does not try to differentiate them further. There are several other pattern and color characteristics that can be used to distinguish between bivittatus and molurus, and between mainland and Sri Lanka molurus (pimbura), but these are not quite as consistent as the orbital scale configuration for the two subspecies. Another note of interest is that I have never seen or heard of a Sri Lanka molurus with the 7th supralabial in contact with the orbit as is seen in some mainland molurus molurus. In Sri Lanka specimens it seems to always be the 6th supralabial that is in contact.
Below are examples of some orbital scalation from my collection. The two pigmented pythons are of Sri Lanka origin. Note the complete lack of an arrow marking on the heads of the two “pimbura”.
Kelly


