The early Rigby hammerless guns and rifles have a similar cocking/opening lever. Also, thier internal cocking mechanism is almost the same, the difference being that the Rigby does not have the swiveling link found in the Woodwards. The external shape of the action is also a common feature to the two. Could Rigby have been using the patent, but not marking their guns and rifles with a Woodward use number? The Rigby I have is marked with a "tB" intertwined and a use number which I believe is for the Bissel rising bite.
The half cock feature is a good one; especially for field use. In the 1870's a fault found with the self-cocking hammerguns was that they were not "safe" as the hammers came to full cock and were ready to go. Woodward, it seems, found the perfect answer: Full cock for shooting with a loader, and half cock for walking up. Note: The 12 bore has rebounding locks, so the half cock feature needs an extra bent in the tumbler. The rifle locks are non-rebounding.