Is there reference material for dictionary abbreviations used in the first half of the 20th century?

I have a lot of abbreviations that I can't work out the meaning of from an old etymological dictionary and I'm looking for a reference that will explain them all.

I have a copy of an etymological dictionary about the Sinhala language, written in English by Wilhelm Geiger (a German), published in 1941. It has a table at the front to explain the abbreviations used for each language's name used but not for the different parts of speech.

E.g. (italicised text transliterated from Sinhala into English):

pahan, pasan a. pprt. pleased, glad

temanavaa v., prt. temuvaa to wet, moisten

mala s., st. f. mal flower

I have highlighted the abbreviations in bold. I have omitted the actual etymologies because they are not relevant to my question.

I can work out that a. is adjective and v. is verb and he also uses adv. for adverb but he uses s. for nouns (the majority of the entries are nouns) and st. f. and st. ff. for single and multiple plural forms respectively (i.e. one mala, two mal using the example above). I'm guessing that he's using the same convension as p=page and pp=pages for the "f"s, st. f.=one plural form, st. ff.=multiple plural forms. I have no idea what prt. and a. pprt. mean. It must have been common enough knowledge for his intended audience that he didn't need to explain these terms. Could it be that even though he has written the dictionary in English that he is using the German abbreviations (s.=substantiv noun)?

Where can I find out what all these (and the others I haven't mentioned) actually mean?