Rod,
Mine was made in 1975.
Throats are about .455", same as my 1980 built 25-5. Got a 2nd mould that casts .455" bullets on the way from Europe as we speak.
Designed for the Webley revolvers and known as "The Manstopper", it is basically a hollow base wadcutter with a crimp groove. With the Model 25's, you never know what you're going to get throat-wise. I have one 25-5 with .455" throats, while another one has perfect .452" throats. Just one more advantage to casting and sizing your own.
Don