Alternating tread stair, and a request for LJ crowd wisdom

Made this to provide access to the loft above the kitchen I was remodeling, and incorporated it into an enclosure for the refrigerator with some additional storage. The rails are doubled thickness of 3/4” oak veneer plywood, with 1×2 oak facing to hide the raw edges. Treads are 3/4”x7” solid oak. Finished with 3 coats acrylic floor varnish.

My request concerns the stainless handrails I ordered from West Marine (4th pic.) I want to face mount them on the upper part of the outer rails. They have 2” of 1/4” threaded rod welded to each end; most boats have access behind or below to install nuts, but I don’t. My first thought was to drill 1” holes with a Forstner bit into the sides of the rails at a right angle to the 1/4” holes so I could spin on a nut, then plug the hole with a 1” oak dowel. But I’m afraid it would work loose over time, with no way to address it, plus the precise drilling required would be tricky with a handheld drill. Second idea was to drill mounting holes for the threaded rods, then redrill at a slightly up or down angle, so that the inner part of the hole had more volume, then fill the holes with fast setting epoxy and shove the rods in, holding in place while the epoxy sets up. In the building trades, anchor bolts are routinely installed in concrete using a similar method. Has anybody ever done this? Anyone got a better way?

-- Tom