the inscription on the second stamp says "Bavarian State Railways", so in the Erler/Juenke catalog this stamp is from the post-WW I 1920 set. It is the lowest value, 20 pf stamp (#41). it is not rare. Three varieties are listed; they are: light green, yellow green, and printed on reddish paper (slight premium).
If this stamp had a "Kgl. Bayer. Staatseisenb." (Royal Bavarian State Railways) imprint, then would have been from either the 1904, 1906, or 1911 series, depending on watermark.