Bob,
First of all, wellcome to ZCS.
For your engines, try this link:
www.zscale.org/articles/revival.html (I also answered, rather shortly due to pressing enter, in the chat window)
That page has a lot of info about reviving Marklin locomotives, including detailed step by step and pictures on how to deal with congealed oil for all main types of Marklin locomotive.
regards,
Kurt