I'll give you a couple of my thoughts on #2...
I think the initials on #2 are I.I.J. in monogram form with the last name initial larger and in the center. Just a stylized form of lettering done to both balance the letters out and add some flair to them.
I wonder about the lack of any engraving on the recvr also, but if not a N/S receiver, then either it had to be annealed to be cut or in the very least, the case hardening 'skin' polished off in those areas to be cut. Perhaps too much extra work for the maker/engraver and he left it plain. The scroll engraving looks to be on the less than 'master engraver' side of the scale.
The more I look at it, it almost looks to me like a plain rifle that was built perhaps pre WW2 because of the stock style and then had some mods done to it in the 50s or 60s from the looks of the carving, checkering and engraving styles. Another explanation for the plain parkerized recvr may be an upgrade through DCM for a free high number receiver to replace the old low# one at some point. A service that they used to offer to NRA members I believe. Just my thoughts! Thanks for posting all the pics. Love those '03 sporters..
