No problem on questions that is one of the reasons for this forum, to help new collectors. So do not hesitate to ask. Regarding ink stamps, many helmets have them but others do not. It is quite legit for this piece not to have them. Concerning the spine and wappen ( helmet plate). Helmets can shrink in dry conditions but not the quarter inch we see here on that spine. I have handled and restored hundreds of helmets.... that is an add on. Original rear spines fit tight to the shell curve when manufactured. With shrinkage, the spine can flatten/deform or the soldered prong holding it to the shell will pop off from the pressure. A gap between shell and spine can also appear. Wappen as well fit precisely when manufactured, they are curved to fit the shell. After 100 years they leave marks in the finish and if not removed, have a century of dust behind them which creates a “ghost “ wappen on the shell. You should also look at the colour of fittings, does the patina of the wappen match the rest of the fittings? Much to consider here feel free to ask for clarification. I would also recommend looking at the posts in the restoration section and new finds section so you can see what good original pieces look like.