Jens
I also have at least some interest in Indian weapons. I had a visit to the national museum in New Delhi 15 years ago, and saw a wide variety spanning considerable time. This was when digital cameras were not numerous and fairly expensive, and I did not take many pictures in the museum. I've been back to India several times since, but have not had the free time I had on that initial trip due to time pressure of the business that was the purpose of the trip.
If you ever go to New Delhi a trip to the national museum would be great for your Indian weaponry appetite. There are quite a number of opportunities in India to learn about the historical conquests and wars, and many fortifications open to tourism that display a variety of historical weaponry.

Although they don't use tulwars as weapons Sikhs in India and abroad use them in religious ceremonies nowadays.
Picture below shows Sikh gurus carrying gold-hilted swords but not tulwars during Vaisakhi celebrations in Southall, England, in 2010 (Courtesy of Flickr).
[ Linked Image ]

In post 21 I wrote that the marks on the blades of the Aydha Katthis were the sign of 'OM'. It is not, it is the first letters of the name of two rulers of Coorg - Dodda Vira Rajendra and Lingaraja.
The information about 'OM' I got from Hindu Arms and Ritual pp. 234-23, but unfortunately the information is wrong.
See The Journal of The Arms and Armour Society. Vol. XXII, no. 4, September 2017, the UK. Pp. 210-220, and A Passion for Indian Arms, 2016. Pp. 224-225 and 228-230.