Well it is an enclosed hammer but there are markings you just need to look better. Their guns are marked on the top rib of the barrel. What dates does it have on the rib? I have a hammer type in my hands right now and the dates are May 14.89 and April 2 95.
My hammer less .38 S&W shows the dates of April 6 86, Feb 18 87, May 10 87, Dec 28 06
The patent datesis how you tell if it is BPCTG or not.