Shortened spellings

[philena.livejournal.com]

I have a question about variations in spelling I've seen. One is of the form of writing an -ие ending as -ье. For example, I've seen достояние written as достоянье. Likewise in declensions, I always thought that the instrumental of, (say, for example) достояние would be достоянием, but I've seen it written as достояньем. These spellings aren't in the dictionary I use. Is it simply an older variation, the way in older English texts you'll see things like deceiv'd or wing'd?

Likewise, for comparatives I've seen both -ee endings and -ей endings. I understand that in rapid speech they would be pronounced the same, but is the second spelling standard in some conditions, or simply a kind of reflection of the pronunciation? If so, when, and if not, how common is it?