Modified uid can no longer see flash drives

[MR ZenWiz]

I'm running Xubuntu 14.04.4 on all of my computers, and I changed the
uerid on my desktop a while ago to something other than what it was
originally.  This worked fine, no problems (after a few hairy things
I;'d missed, and the login greeter will not display my userid in the
chooser, so I turned it off - how I don't remember, but it works
fine).

However, this userid did not match the uid on my laptop (1000), and it
got picky a week or so ago  with cross-machine copies.  I decided to
change the uid to match (1000 -> 500).  I thought I'd covered all the
bases, but alas, things have not been so nice.

For one thing, I can't get the login greeter to stop showing me the
"Other..." choice (I had to disable the Guest account to get this
far).  It will let me log in with my user id and password without
having to click past the Guest option, so that's just a minor
annoyance.

The big problem is that when I insert a flash drive, it mounts, but I
can't see or access it unless I sudo everything, including df (just to
see that it is mounted).

I googled for this, but none of the answers works as needed.

The permissions for the drive look right:

$ sudo df
:
/dev/sdb1 ##### ##### ##### ##% /media/admar/Lexar

$ ls -l /media
drwxr-xr-x+ 3 root root 4096 May 30 17:09 admar/

$ ls -l /media/admar
/bin/ls: cannot open directory /media/admar/: permission denied

$ sudo ls -l /media/admar
total 4
drwx------ 58 admar admar 4096 May 30 14:57 Lexar

I (admar) am a member of the root, fuse and plugdev groups (actually,
most of the system groups, but these were called out in various web
pages).

I have not been able to find any configuration file under /etc that
shows a clue on this, but I'm not entirely sure what I should be
looking for - my current user id, my old id and the old uid don't turn
up anywhere that makes sense.

So how do I get the system to recognize that I mounted the drive and
should have access to it without having to assume root privilege?

Thanks.
MR

PS: On my work desktop, the drives don't mount automatically at all -
I have to do it manually with udisksctl, and I didn't mess with the
uid at all.  Another curiosity, but that one is more manageable.