Vintage mini NBC pocket iron issue

Hello all. Picked up this vintage Nat. Billiard Co. half scale table (playing surface 56"x28"). Full size framing with stamping indicating it was built between 1900 and 1910. Has 3/4" slate. Table complete EXCEPT (big except) it has no pocket irons. Pictures show it had nets on it at some point, but I don't know if these were original. Holes in rails indicate it needs #3 pocket irons, but they need to be smaller than normal. Have searched everywhere and called the leading pocket iron experts, but they haven't given me much hope of finding what I need. The holes for the pocket iron bolts are 5-3/8" center to center on the corners, and 5-7/8" on the sides, which is an inch or so under standard. Please give me your thoughts on making a set (how, material, etc.) vs. going to a top mount snooker bracket style, presuming a closer fit could be found. Thank you!

Slate Humper: You are correct! Thanks for that great steer! Hopefully it will pay off one way or another. Between his and mine, we have a whole table!

Thanks Rob. I did speak to Ken - no luck. G irons way too big. Need a 3" opening. Thanks for your thoughts though.