Some violent and notable pre-1990 Bangladesh-East India tornadoes:
4/8/1838 Calcutta, India:
This tornado was deadly and slow-moving with a forward speed of ~6 mph. Homes were reported to have "vanished," grass was scoured, palm trees were debarked and a large peepul tree was uprooted. 215 people were killed by this tornado.
4/19/1963 Cooch Behar, Bangladesh:
This is the tornado that Fujita gave an F4 rating. Homes were completely leveled, trees were completely denuded, bamboo groves were uprooted, and ground scouring occurred in paddy/jute fields.
4/11/1964 Muhammadpur, Bangladesh:
This extremely deadly and violent tornado devastated multiple villages in the Muhammadpur Union. Entire villages were wiped out with one reporting to have no survivors. The death total might have been as high as 1300 but this can't be confirmed. "Three unions comprising seven villages of Mohammadpur under Magura subdivision were wiped out without any trace of human habitation." I wish there was more information available about this tornado as it sounds pretty violent.
4/17/1973 Manikganj, Bangladesh:
This tornado devastated the Manikganj subdivision. Eight villages were leveled. In one village "not a single dwelling was traceable." The official death total is 681 but the unofficial death total is 1000. A "pucca" (dwellings that are designed to be solid and permanent) concrete structure was moved a few meters.
4/26/1989 Saturia, Bangladesh:
This is the most famous of all the Bangladesh tornadoes due to it being the official deadliest tornado in world history. Homes were completely leveled, trees were denuded and 1300 people were killed. The WMO rated it as a mid-end F3.