Rather curious that the forend tie plate on that uncompleted 71L rifle has been welded. Presumably the brass crosspin replaced with steel? The routing out of the recess looks a bit different from normal as well.
I wonder if this was one of those rifles put together from left over odds and ends as apparently happened at Long Branch - SAL. A number of rifles of various configurations have turned up assembled from various parts. Could this be an experimental tie-plate system? Decades ago I spoke to a former RCN engineering office who was a technical inspector in some capacity for the federal government in the 1950s and 60s, who mentioned having a rifle made up there as a retirement present for a colleague, as this was a largely unprompted recollection and he mentioned the rifle "even having the tag on it" etc. I thought it a pretty reliable statement.
There is another uncompleted Long Branch rifle for sale online at the moment.
This 71L was stripped by Parker Hale and D&T for their mounts.
I've seen one or two that were done by "Santa Fe" in the past.
One of my No4T rifles was a retirement gift, the wood sanded and poliurathaned, and all the metal was spray painted silver.