The model 605 is the 357 mag version and it has 3 finger grooves, I believe they are the same frame so you might want to try a 605 grip. I would verify this info before I bought them though.
Bruce Banner has hit the nail on the head. The M605 has the longer grip. I ended up buying this model. Alas, my M85 sits in the safe.
BTW, Bruce, do you turn all green when you get angry???