Battery Charger Rebuild

I have an old battery charger that I would like to rebuild. The cords (120V in and 12V out) need to be replaced. I am wondering about changing the old rectifiers for a new bridge rectifier (bridge). My questions is how.

The power comes in and one leg goes to a switch (6V or 12V) then that come into the transformer via the black and yellow wires on the bottom. The other leg comes right to the top of the transformer. I have checked all of these and they have continuity between them and the switch works.

Coming off the transformer on wire goes to a ammeter and then the two other (smaller) wires go to the rectifiers (mounted to the back wall). One wire comes off the rectifiers to a "block" (maybe a fuse?) and then goes to the clamps. The other clamp connects to the ammeter. The "block" has continuity between the posts.

Do I just replace the rectifier with a bridge (where do I hook the leads off the transformer) and I assume I hook the wire coming off the rectifiers to the positive output from the bridge. This would leave the negative post open.

Attached Images
File Type: jpg Charger 2.jpg (53.3 KB)
File Type: jpg Charger 3.jpg (46.7 KB)
File Type: jpg Charger 4.jpg (42.8 KB)
File Type: jpg IMG_20200101_140838931.jpg (53.3 KB)