The Sun Center Publishing Co?

I stumbled across a letter (ok, more accurately put: I stumbled across a scan of a letter) from 1911 sent to an R. A. Bell in Montana:

Dear Sir:
In response to your kind enquiry, we take pleasure in forwarding you particulars of the New Lessons in Physical Regeneration. If you are greatly interested in the study, kindly write for any further desired particulars.
Yours truly,
The Sun Center Pub. Co.

This brief note suggests so many interesting projects, not the least of which is: What on earth was this course, New Lessons in Physical Regeneration? Who was The Sun Publishing Company? What else did they publish? And really? Are you seriously promising immortality, physical immortality? I might have to check the IAPSOP to see if I can still get the lessons.

How can anyone say history is boring?