I am continuously learning, as well as having fun with this little cartridge and the old rifle. 
It appears (after trying 3 different ones) that the best case forming die for it is a full body 32-40 die cut shorter. Mine is the RCBS cowboy die, which i had shortened by the difference in case length between .32 Ideal and .32-40 (the difference is 0.28" ).  This die will decap and make a gentle sloping squeeze on the upper 1/3 of the case, and the cases are not worked too hard and remain concentric. The shortened neck die for 8x57 squeezes too much of a neck on the case, even makes a small shoulder, causing the bullets and entire cartridge to be eccentric (the center of the bullet is no longer at the center of the case and or bore). 
The CH4  full body die made for .32 Ideal really abuses the brass too much, squeezing the entire body of the case. I would not use it because cases will not last long.. 

Any shortened 32-40 or 8x57 bullet seating die works, but the crimps may be different and the seating stem may need to be polished to match the bullet nose.  Of course, the seating die needs to be shortened by 0.28". 

I am using a Lyman M die to expand the neck and flare the case mouth. The expanding stem is .320", possibly not enough for .325" bullets. I will try larger expanders, to try to get the brass to expand no more than 0.002" when seating a bullet. 

A few rounds loaded with 12 grains of 4227 produced consistent velocities at 1,350 fps.   Accuracy unknown, i just shot a few over the chronograph.

I am using Bertram and Rocky Mountain brass. Bertram is splitting even after annealing and is really thin and brittle. Rocky Mountain seems good quality.