It looks more devanagari than ranjana to me.
Yes, but I wrote "influenced".
I think I can recognize some of the letters, especially when I turn it over.
I printed and turned, it and yes. What puzzled me besides that right-leaning flourish was a letter that I think is a ya य; it occurs with a stroke in it which should be a Sha ष, but the outline is a mean value of those. On the other hand, my assumed ya looks pretty much like a pha in the Modi script
I bought this book in India. I assumed this was an old form of devaganari. Do you know?
I read written devanagari, and sometimes manage nicely handwritten Hindi, but I manage few letters in your book. The ':' suggests Sanskrit. At the end of the 3rd last line there is what might be ligature of ङ and ग, giving the ending 'ng-gaah'. 'ng' fell into disuse long ago and was replaced by the nasalization dot above.
So, not finding perfect correspondences on the Internet, I think '(old) devanagari versions' is probably the best we can do.