Contrary to popular belief these now iconic side claw mounts were not invented by Holland & Holland. Instead, Austrian gunmakers used near identical mounts before WW1 to mount Kahles "Mignon" scopes. Many Steyr Mannlicher M95 straight pull sniper rifles were mounted with such side contra/inverted claw mounts with the rear hook going into a set-over base and the front locked by a lever. These mounts depend on both feet/rings retaining exactly the same distance, with a bit of pressure fore and aft. The Austrians licked the problem by soldering half-rings to their steel scope tubes, making them immovable, the scope tube taking care of the proper ring spacing. When H&H adopted this mounting system they wanted to clamp the scope in full rings instead of soldering. As such rings may slip a tiny bit, or the scope may be exchanged, H&H added such spacing rods to keep the rings at the proper distance all the time.
BTW, I would prefer a sleek contra claw mount like those Rigby once used to the somewhat bulky H&H side mounted type. On the Rigby type, the rear ring hooked into a square hole in the receiver bridge, while the front ring went into a base on the barrel, in front of the receiver ring, locked there by a lever . Just as solid and reliable like the H&H mount, but much less obstrusive. This Rigby –Mauser mount was the original reason for the square bridge and the stepped receiver ring, to provide clearance for the scope locking lever, of the early Magnum actions. See this .350 Rigby:
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