Maybe by some miracle they used PVA (white glue/like Microscale Krystal Klear).. try soaking a joint with some water, maybe a little ISO alcohol if it turns white, you're in luck. if not, it might be a tough one.
Are you going to repaint it? If so--the bath of paint dissolver usually loosens such joints.
Finally, you might be able to find a replacement set of handrails and then just carve off the old ones/clean up/redrill mounting holes.