I have some mp3s and would like to know wich lame-settings were used to
encode them.

Using encspot pro, I can only 'retreive so much' data about used settings.
(right-click file, lame header)

If I give you these screenshots from encspot:




Can you guys help me find or suggest (as accurate as possible) the used settings
that were used during encode?

thanks.

Judging by minimum bitrate & lowpass, looks like it was encoded with the old "--preset standard". It's not quite possible to tell if some additional switches weren't used.

Mr QuestionMan can identify the version of Lame used and the settings, such as presets, abr, et cetera.