Jim I can see it both ways, especially given the prevalence of side-openers in PA including a couple that are quite similar to 42 (including the need for the awkward clearance gutter along the lower edge, before the Bucks Co. guys fixed the issue). However, some of my thinking has changed in more recent years. I want to be clear, I don't think it's possible one way or the other to definitively determine if the 42 box is a very old replacement, and so I would tend to take it at face value. What I would say is that *if* it were a very old in-period replacement (i.e., say 10 or 20 years into it's lifetime) for one of those cast captured lid boxes that mimic its shape, given the huge mortise that is now present in 42, all evidence of the original box would have been obliterated. One thing I don't buy into is the concept of the coil spring somehow meaning something or being indicative of something; its a coil spring of a type found in use in other objects of the period. Someone thought 'hey, this will work.' Whether it was the original stocker and the box / spring is original, or someone wanting to fix a problem who had such a spring on hand - I have no clue, but I don't think that the coil spring somehow points to anything specific. Just my own thoughts.
The box on 43 is a fairly substantial casting of a later period and once again, it's installation would have essentially obliterated any sign of a wood box lid assuming the box side rails were cut in a traditional manner and not half an inch deep like many today unfortunately do!
