[CR]Simplex shifters and related things

A few questions and a request-

What are the generally accepted cog size limits on a Simplex rear short cage SLJ derailleur, circa. list time period limits? Are they more accepting of 28 tooth cogs than the Nuovo/ Super offerings of the time? Also, what are the shifting limits of a similar Simplex SLJ front triple

derailleur? Any guidance here would be helpful.

Also, does anyone have a set of clamp-on Simplex retrofriction shifters that they would willing to part with for a reasonable price? New is preferred, or down to something leaning to the excellent side of good condition is fine. I just don't want to pay this much for something like

this:

http://tinyurl.com/ht07

How reasonable is that price for the earlier retrofriction? Really, is that reasonable? Perhaps, as I've been sometimes told, I'm just plain unreasonable.

Thanks to all-

Vince Connelly
Baltimore, Maryland