Atlas mudguard stays conundrum

Okay, perhaps I am overthinking this situation but here goes: I have a set of chromed mudguard stays for my Atlas (they are in excellent used condition - good chrome, straight, etc.). The lengths are spot-on but the ends of the stays do not rest flush with "D-shaped" thick mudguard washers (not even "almost flush"). So, do the flat ends of the stays require some "persuasion" or am I missing something? I have combed the manuals and the exploded parts diagrams on Andover Norton's website but just can't tell.