Bullets.com has an order that is about to arrive in the US
http://bullets.com/products/6mm-Dasher-F-Class-Brass-Case-of-100/BL11293
They have given it a longer neck (1.555 bolt face to end of neck for the 6 Dasher reamer and 1.605 bolt face to end of neck for the 6 Norma Dasher reamer.) The throat and lead are also pushed forward about 0.050 on the 6 Norma Dasher reamer to match the 0.050 longer neck length.
This is going to be a very popular cartridge, I suspect.
http://bullets.com/products/6mm-Dasher-F-Class-Brass-Case-of-100/BL11293
They have given it a longer neck (1.555 bolt face to end of neck for the 6 Dasher reamer and 1.605 bolt face to end of neck for the 6 Norma Dasher reamer.) The throat and lead are also pushed forward about 0.050 on the 6 Norma Dasher reamer to match the 0.050 longer neck length.

This is going to be a very popular cartridge, I suspect.