Doc,
Sorry you had to re-register at FSM. At least your name is still Tanker Builder. FSM should be able to get you back to your old log-in though. Try'em.
I recall awhile back you had some help with posting your pictures from a member here. Try that source again for using the Flickr Hosting site. Alternately, young friends and family can be indispensible.
Your other issue:
I gather the Avatar you want to update is the one for FSM? If so...
Log onto FSM.
CLICK on your existing Avatar photo (It is currently a "default" image.)
Click EDIT AVATAR (under the Avatar Picture).
A small window called CHANGE AVATAR opens
Click BROWSE.
A new window opens. This will be your computer showing your files. You can now browse around your folders and files.
Find a photo for your Avatar, double click on it. (or just click OPEN.).
The CHANGE AVATAR window appears.
Click UPLOAD and USE IMAGE. ( Your new Avatar image appears)
That should do it BUT...
I do know of one instance where a member could not update their Avatar. Take a look here in case this is your issue.
LINK: http://cs.finescale.com/fsm/feedback_help_and_testing/f/39/p/163520/1788035.aspx#1788035
In the mean time I have a PM coming your way.
Jim.