357 Taurus - cylinder won't open

I have a 6-shot, large frame, Taurus's .357. It has no model number, but when I enter the s/n into Taurus database, it says built in 1992. Can't find any parts manuals that even look similar (vent rib, combat trigger+hammer, fully adjustable sights). I took it out for the annual cleaning and the cylinder won't open. The thumb release is clearly working and the rear of the cylinder begins to roll out, but the front at the end of the extractor rod doesn't budge. The extractor rod fits up into a grove below the barrel and there's no way to get anything on it. When the cylinder is spun freely, the extractor rod rotates with it. There appears to be a pin in front of the rod. Is there like a spring loaded ball bearing that snaps into the rod when closed? I let some CLP soak in overnite, still bound up in front. It's unloaded BTW. Thanx in advance for any suggestions.