Before assembly, check the fit and remove the release agent with isopropyl alcohol or acetone. Cut off sprues with a saw/cutter. Wear a dust mask or respiratory mask when machining to avoid inhaling dust particles.
Carefully heat warped parts (e.g. with a hairdryer) and bend them into shape. Glue with 2K or superglue. Unpainted cast parts darken over time and can turn yellow - especially when exposed to UV light.
Corduroy pants: stone gray; Side seams red Tunic M1907: field gray Work suit (jacket): Black Drillich; Buttons as well Boots: blackened leather Field cap: field gray, trimming strip black; red seam; cockade (for example Prussia black / white / black), above German cockade (black / white / red) Igniter (cap): brass Bomb body: