This has been a long standing problem with TKM. I have never found a website for Michel Avionics but I did find a dealer who has a manual page at http://www.hawkinsassoc.com/tkm_manuals/manual_main.html Unfortunately they only have a lousy scanned copy of the MX300 manual there, nothing else.

Because I have an MX300 and get lots of request for copies of the manual I took the trouble to convert the MX 300 manual into true digital files (both HTML and PDF)last year.

These have been available in the member's area for several months.

I'll be happy to do the same for the MX385 if someone wants to send me a photo copy of their MX385 manual.