Coincidentally, like you ntloop I had been away from Bristol for a long time (16 years in my case - I used to live there as a student for three years).
I returned for the first time, a couple of weeks ago. I did not have time to check things in advance so I was surprised to see the ticket barriers there, as of course they weren't there back in the early '90s!
I didn't have time to ask anyone for permission to take photos either as I had a full itinerary for the day, in Bristol and had to get out of the station pretty rapidly.
I did take a few casual snaps on my cheap camera though, as I'd arrived by train, the barriers weren't an issue:-
http://i77.photobucket.com/albums/j7...l/DSC05668.jpg
There was a frieght train in the station too:-
http://i77.photobucket.com/albums/j7...l/DSC05881.jpg