oslexam.dll (from IBM Works) is still available on Petr Mikulík's page:
http://www.sci.muni.cz/~mikulik/os2/zdroje/oslexam.dll. Dont use lexam.dll from epm_spel.zip. It's outdated (package is from 1992) and not made for EPM 6.03b.
The most recent dictionaries come from Netscape 4.6.1. Note that they have the extension .dic (not the older one, .dct). Just a few months before IBM closed the download page, I had downloaded them all. (Quite recent ones were also available on the LEO archive, but the OS/2 part is down.)
Not that not all dicts work. E.g. I remember that the turkish dict traps EPM. The UK dict should work. Some features may not work like proposing alternative words. This disadvantage applies for deutsch2 (after the German spelling reform), but not for the older deutsch.dic.
I planned to upload the dictionaries to Hobbes, at least shortly before the first beta of NEPMD 2.00 will be made available. (For a recent version just compile the recent NEPMD sources, IBMCPP 3.08 or CSet/2 is required, or send a private mail to me: forename.lastname at web.de) It contains oslexam.dll and has code to switch dictionaries since a quite long time.