Darn it, Gary, I knew I shouldn't have made the comparison.
Here are a couple of images of my .400 Whelen project rifle's Lyman 48 peep that Michael helped me find. Damaged in shipment, damaged before packing I couldn't say but damaged it is. Both 2-56 windage unit retaining screws were sheared off and the windage screw was bent and partially broken. Fortunately Michael had some spare parts and I got the sight fixed. In return, I repaired two of his with the precise same damage. Two old-timer friends up here that have considerable experience with the Lyman 48 have told me they have also had the windage knob bent or broken in the same fashion.
It is the classic peep, I prefer them to all others and will continue to put them on rifles when I can but, respectfully, ruggedness is not an attribute I apply to them. When looking for rugged you need look no farther than the Recknagel peep but boy is it ever ugly.
Brent--Sorry, I have no experience with the 54's.
Dennis