Your image posting doesn't seem to have worked, possibly because of an unsuitable image hosting site. https://postimages.org is recommended (click 'Share', then copy and paste the 'Hotlink for forums' code to embed your images).
Those are pseudo marks (Augsburg acorn,crowned letter pseudo Paris mark) used on remake or fantasy pieces of old silver. Although there is 13 Loth old German standard, the box was made in the last decade of 19th century, or even later. Regards
13 (Loth) means .812 (i.e. 81,2 %), i.e. solid silver. 13 Loth was common standard in German speaking countries. Neresheimer is a reliable maker, so there is no doubt about the fineness. Regards