Huvius; I am not absolutely certain but I don't think any actions were made specifically for shotgun usage, that "shield" is most likely "soldered" on. This was only done on the Remo all the others were screwed on with two screws. That thingy under the ejector is part of the shell retaining / release system again this method is only on the Remo. The "mushroom" on the front of the bolt is pinned vs held by the extractor on the others.

The stock on the one in your pic. is not original but a modified military - well done though. The Remo had a nice rifle type stock side panels, cheek piece and all. All the rest had cut down military stocks no embellishments.

A write-up on these is in "Bolt Action Rifles by F. de Haas" another on the Gunboards site. In Franks book he alludes to the fact the 98 Remos (not to be confused with the Remo-popular which is based on the Mauser 71) are rather scarce likely due to cost. The Remo all in all is more refined and complex when compared to say a Geha etc.

I have pics. of mine and can Email to you / anyone willing to post. FWIW --- John