Look to see if any of your TC's have the three hole tang. If so, this is for mounting the Lyman Peep sight as well as the one that TC use to sell and can still be had. Lyman also has the front globes...
Now then, there are a number of verniers out there and some are not easily identified as to who made them. Dixie list as few but keep in mind that the CTC on the tang, will vary. I like the look of the shorter veriers. Sometimes you will see them listed on eBay or GunBroker.
I just went into the Lyman website and could not find the 57SML peep sight. ..
Be Safe !!!