I have been doing a bit digging around on the net. I managed to find an online copy of Johannes Vehlow's monumental 8 volume work Lehrkurs der wissenschaftlichen Geburts-Astrologie. Vehlow discusses his proposed equal house system (which cusps in the house centre) in Volume 1 which was published in 1933. This was two years before B.V. Raman's book appeared.
Vehlow had obviously been working with this system for several years before this publication. He doesn't mention any Indian influences in proposing this house system. Instead he seems strongly influenced by the Solar cycle and Egyptian mysticism. Vehlow points out the traditional orb of the Sun is 15 ° right and 15 ° left and imagines it rising on the ASC degree.
However, Vehlow does quote an English astrologer called EH Bailey who had written two articles in the ''British Journal of Astrology" from 1928 who advocated equal houses with central cusps. Bailey himself does attribute the idea to 'Hindu astrology' and quotes the astrological text of Sripati. At present he appears to be the first astrologer to propose this system in writing.
Although, from the quote Therese gave B.V. Raman may have been using the system successfully for much longer in private.
The vedic calculation tab of the configuration dialog has the option to switch between sandhi view and cusp view (check box K.P. Style House System).
Configuration of Houses
House systems can be configured separately for Vedic and western astrology in the Configure Western Calculation resp. the Configure Vedic Calculation tab of the configuration dialog.
Astrological Objects Articles Calculation