In India: From Midnight to the Millennium and Beyond
Chapter 2 - Two Assassinations and a Funeral: The Death of a Dynasty by Shashi Tharoor Google books can only find one mention of "thumbs" and that is in relationship to the Thumbs up brand of cola.

But wikipedia links to a page that links to:

The Telegraph - Calcutta (Kolkata) | At Leisure | Found: Raj-razed town

"I began from zero. There was no trace of the town; the Basti district map had no reference to it," Ansari, a textile exporter who began his search in 1994, told The Telegraph. "But I was adamant. I had to verify what I had heard from family elders about the town that our ancestors had fled after the British razed it during the 1857 revolt."

His persistence prompted the then Basti district magistrate, R.N. Tripathi, to set up a committee of historians from Lucknow who, after 13 years of research, have now confirmed that the town indeed existed, at a spot 15km south of Basti town.

Ansari feels he has paid off a debt to his ancestors -- which is what some of his forbears in Mahua Dabar too must have felt when, in the first weeks of India's first war of independence, they attacked a boat carrying British soldiers.

They had reason to feel vengeful.

In the early 19th century, the East India Company, eager to promote British textiles, had cut off the hands of hundreds of weavers in Bengal.

Twenty weavers' families from Murshidabad and Nadia had then fled to Awadh, whose nawab resettled them in Mahua Dabar and allowed them to carry on with their livelihood.

Many of the first-generation weavers had already lost their hands, but they taught the craft to their sons and the small town of 5,000 people soon became a bustling handloom centre.

It was around March-April 1857 when Zaffar Ali, a young man whose grandfather had migrated from Bengal, spotted a boat coming down the Manorama (a tributary of the Ghagra) on whose banks the town was located.

The historians' report names the six soldiers beheaded: Lt T.E. Lindsay, Lt W.H. Thomas, Lt G.L. Caulty, Sgt Edwards and privates A.F. English and T.J. Richie.

On June 20 that year, the 12th Irregular Horse Cavalry surrounded the town, slaughtered hundreds and set all the houses on fire. The Raj decreed that no one could live in the place from then on. On the colonial revenue records, the area was marked gair chiragi (non-revenue land).

Mahua Dabar ceased to exist.

The Telegraph - Calcutta (Kolkata) | At Leisure | Found: Raj-razed town

The historians' committee -- headed by V.P. Singh and including J.P.N. Tripathi, both former Lucknow University teachers -- kept digging into the district museum archives.

Yes, names! Haven't been able to find the actual report, but from an article about it:

Unearthing a Gory History | OPEN Magazine

Archives at the National Library in Kolkata, accessed by Open, show that the British chopped off the thumbs and hands of master weavers in Bengal, and many of them fled with their families to other parts of India. About 20 such families sought refuge from the Nawab of Oudh, who settled them at Mahua Dabar, a centre of weaving and dyeing near Basti.

So Indian sources it was.

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