Ugh, too many hours at work to buy toys later, no play time. Pushed on through tonight. I used two of the GRK fasteners (#10 by 3 1/8) to secure the nut to the back of the vise leg. I think the screws that came with the Anchora chain kit are going to have to do. The exposed end grain is front stretcher tenon that is about to get butchered. If the screws pull out I will use through bolts and countersink the bolt heads on the front side of the leg to not interfere with the chop.
And I finally have a plan. I am going to stick with the 3.5 width for the parallel guide. That will basically destroy the existing butterfly on the front of the chop, but I saved my butterfly shaped scraps and can drop another one in no problem. That will leave about 3.5 inches of relish on the chop from the parallel guide mortise. If it breaks I would rather replace the chop than have to dip into my small stash of well seasoned white oak for a bigger parallel guide.
20210324_205026[1].jpg20210324_205107[1].jpg20210324_205048[1].jpg