I'm assuming you haven't got a blue edit option below the post you are trying to edit? View attachment 185
I've tried fiddling with your permissions, but I'm not sure what I've tried to do will fix it. I'm afraid you might have to wait until @Shaun is back on line.
I can see the Edit link in my own post in there that needs working on, but that doesn't necessarily mean anything, as moderators have a slightly different set of permissions.
I haven’t found the pre-publication forum but have noticed I don’t have an edit option in the old posts I have made. I can’t for example correct spelling or punctuation errors. There is the option in new ones.
That is due to how the usergroups work. As you post more your permissions and time limits are expanded. However, on review, the new member limits were a bit tight for editing so I've modified it and you should be able to see the edit link for posts up to 30 days old now.