even that I'm oficially at the vacation I couldn't resist to take a quick look at what you wrote . Denise - what you have written is actually very, very helpfull because i found a small detail that certainly had an influence on the gelatin and caused frilling on the edges and making the surface of the whole plate "fractured" (not sure if I'm using the word correctly - it's not smooth, looks like the surface has a lot of small grains or dots...). And the reason is the temperature changes! I always used developer at room temperature (so about 21-25 C), very cold running water for stopping wash and fixer also at room temperature. So there was actually 2 temperature changes. Now that i think about it, it surely was devastating to gelatin, weird fact is that it didn't came off completely.
About chrome alum - a have a small stack and it's possible to get more. It's actually more difficult to get real photographic products (like Kodak Hardening Fixer and other un-typical thingies) than chemicals to make ones That's why I made the developper and fixer that Marc is advising (MQ developer and Hypo fixer).
Anyway, I'll surelly peek here some time during my vacation (probably tomorrow :P), so feel free to comment and correct me.
Thanks and Cheers!