Randip ji

Your own response is interesting! And thanks for the historical reference. The Chumar sub-caste historically followed many Sikh devotional practices but also there is also worship of Bhagat Ravidas. They see no contradiction, read the Sri Guru Granth Sahib, conduct akand path, and at the same time perform a Hindu arti and claim Ravidas as their personal Saint. The followers of Ravidas claim that Ravidas gave Guru Nanak copies of his hymns.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/bhagats/22222-who-was-the-guru-sahib-kabir.html

There is an entire belief system called the Kabeer Panth whose Granth is the entire collection of hymns of Bhagat Kabeer. Again their devotional worship includes monotheistic belief, and other concepts found in Sikhism. But it is very very different.

Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=22222
Both panths have gurdwaras around the world.