In-game there's only spyglass item, and with item_display set to head, firstperson_righthand and thirdperson_righthand it renders its 3d model. In the editor, when those values are set, it still renders as it would in gui. Then there's splyglass_in_hand, which is not an item in the game, and in the editor it has different offsets with values from above compared to how it's in the game.
In-game there's only
spyglassitem, and withitem_displayset tohead,firstperson_righthandandthirdperson_righthandit renders its 3d model. In the editor, when those values are set, it still renders as it would in gui. Then there'ssplyglass_in_hand, which is not an item in the game, and in the editor it has different offsets with values from above compared to how it's in the game.