I do not know. This is not something I have studied but I know there is a lot written on Roman coins that traveled a lot further north than I would have expected. Almost all of it is in languages I do not read. For example, the bibliographies on these links are not small but probably not very inclusive either:
http://histoiremesure.revues.org/886
http://www.archeo.uw.edu.pl/zalaczniki/upload800.pdf
http://ww.archeo.uw.edu.pl/zalaczniki/upload670.pdf
The last, in particular, covers bronze coins of a similar period. Finds are very hard to study privately since relatively few countries other than the UK encourage private search for treasure. Elsewhere, where such activities are not legal, a find (accidental or searched out) is as likely to be melted as it is to be reported.