Hi Colin, yes that's exactly what I'm getting at. Accounts like the following from 1932 in Khartum (The Mahdi of Allah: A Drama of the Sudan) make it seem like weapons done up to appeal to tourists were common.
Finally, as I do not understand any language at all, the Parsee winks at me mysteriously and produces a bundle - one that can speak for itself! In this bundle there are weapons - spears, barbaric clubs and shields, daggers that instead of sheaths are stuck into small dead crocodiles, so that the hilt protrudes from the jaws; and, above all, swords of an unmistakable form. The leather sheaths end in curious rhomboid-shaped points; the hilts in the form of a cross are studded with silver; the blade, when you draw it, is straight and broad, not a Saracen scimitar, but more like a Crusader's sword.
These weapons, too, might be faked. And, indeed, they are. Weapons like these are being offered to tourists in the mysteriously beautiful bazaar lanes of Assuan as Dervish trophies from the Sudanese battlefields.
The Indian curio dealer is standing in front of me on the lawn with a great naked sword in his hand; the gold embroidery on his little cap is sparkling in the sun and he is shouting at me words which - no matter in what strange language of the Sahibs I may happen to think - here in the Sudan I am bound to understand:
"Dervish, Sahib! El Mahdi, Sahib!"
"The sword, la espada, Sahi, Mynheer, of the Mahdi!"
Blair Castle has a great collection, but it is all quite workmanlike and there are no croc or fancy weapons on display.
Most of the Thuluth and croc pieces I've seen in museum collections like Pitts river have ascension dates from the 1920s or later. Although some thuluth peices are of course certainly Mahdist period and reached museum collections at the end of the 19th and very early 20th century like the piece linked below.