I went with the Williams 5D on my 1894 and 1895 Marlins and my buddy mounted the FP on his. I liked both of them just fine, sturdy, set screws to lock in your adjustments and the FP click adjustments were tight and in synch. I did not like either on the 1894 ultimately as when it was mounted in the rear scope holes it over hung the hammer. This was also a less durable position, as I knocked one off sight during a hunt while skidding down a hillside. It looks like Williams now has an FP and FP-TK (target knob model) for the 39A that mounts in the new model scope holes as well as the original that side mounts.
I added a .125 aperture brass ringed 'twilight' for hunting, although the .093 was mostly fine the larger was better in little light, and a .050 for target work and had a fine time with them.
If you're happy with the mount on your Golden, I'd recommend them just fine.