Veritas 300/400 mantels any good ??

nice, i would get them and let them run on a 350hk Petromax, they will be too small for 500hk.

Best results i achieved with 500hk Luxor mantles, i had a 500hk-lamp in my car for 15.000km and the mantle still was not broken.
The mantles are bright white with a touch of purple in the light colour, non radioactive and very strong.

good luck, Björn