The markings found on the Gasplane reveal who the manufacturer was, when it was made along with other production details. The common method of applying markings to the Gasplane was via a paper label. They will also be found applied directly on to the Gasplane and with labels made using materials other than paper. The information presented does vary depending on the manufacturer.
The labels had a practical purpose because they served as a visual indicator where the Gasplane should be held when being deployed. For those Gasplane which had their markings applied without a label, they usually have coloured squares to serve the same purpose.
Deciphering the markings
The first line has the letters a g d which is the code used by Deutsche Linoleum-Werke A.G., Bieetigheim, Kr.Ludwigsburg.
The second line contains production information. The number 229 is perhaps a batch or run number which is followed by the year and month of manufacture; May 1944.
The number 80 is for the number of times the Gasplane has been folded. On some labels the 80 has the suffix “g” which may stand for gefalten or folded/pleated. (Thanks to SF Mike for this information).
The final information shown; Mo Ap, I think are abbreviations for the materials or chemicals used during manufacture. I have reached this conclusion by reviewing labels of other Gasplane’s especially those made for Tropical and Arctic environments because in the examples seen they have Ope which is an abbreviation for Oppanol and similarly Ly for Lyafol. Unfortunately I have not yet found out what the abbreviation Mo Ap is for so if you do know please get in touch.