Not to deny your services to Thackerites but scourging the interwebs, it doesn't take much to realize these sanghis only consider Hindus their own. Their veneer of a forged alliance with even their Dharmic brothers, the Sikhs and Buddhists shatters if a Sikh or Buddhist starts exceeding his bounds- ask any Khalsa Sikh that. Bon chance for your endeavors though.
If you think Marathas are sanghis you know nothing about local Hindu groupings in India.