I regret that I mistakenly posted my Denarii in this thread instead of Surprising Variations of Denarii... I have removed them and migrated them to the proper thread. I regret the interruption...
@zumbly and @dougsmit when I read that 1910 article I thought about coins I have seen before with numbers either stamped or written on them. Apparently 100 years ago that type of thing was not frowned upon. I wonder, did Mr. Krauz's relatives understand his cataloguing methods? He seemed to think they would.
I'm a fan of trays. I like to display my coins. I'm probably impressing nobody but myself with my awesome portrait collection of rulers. Trays suit me because my collection is limited - I'll probably expand beyond portraits of just Roman/Byzantine rulers eventually. But I don't see my collection being bigger than a few hundred coins.