Sorry folks for not posting a update...
I never heard back from Seekins so I went with the Accu-Shot BT15 rail section. Perfect fit! I also picked up the BT1517 fastener kit. T-nuts and longer cap screws.
Money well spent with both. About $31.00 shipped from B&T direct...
I'll post a pic here in a couple minutes... Just need to access the safe.
ETA: Access granted...