Cox and Luckman – skew mouth plane
Hi, to answer your query:
1. your hollow moulding plane has a skew mouth to help prevent tearout when encountering cross grain.
2. Cox and Luckman started as Planemakers from 1839 until about 1876 at Union Works, Darwin Street, Birmingham, England. From then onwards, they occupied premises at Stanhope Street and ultimately Gooch Street, both in Birmingham. They were very prolific makers of all types of carpenters, joiners and coachmakers planes. sometimes they also marked the planes with London to try and add saleability to their products, in a competative market.
So, the answer to your second query is that theyier planes are not particularly rare. Use it rather than put it on a shelf to look at!
Hope that all helps,