[Rd] R license for a derived data-only package

[Michael Friendly]

I'm looking for guidance or advice about the R license to use in 
preparing a package containing the
Baseball Database from http://baseball1.com/statistics/
My main purpose is to make it available to students in a course, and to 
develop it with others
I'd like to put it on R-Forge, and then perhaps make it public on CRAN.

However, the page above bears a very restrictive copyright notice and 
limited license:

This database is copyright 1996-2010 by Sean Lahman. A license is granted
for individual use for research purposes. It may not be re-distributed
without permission. Any commercial use, or other dissemination of the
database in part or in whole is prohibited. Use of this database
constitutes acceptance of these terms.

I've written several times to the author asking permission for my 
intended wider use, but have
received no reply.

What makes this perplexing is that I am apparently free to "distribute" 
this by sending links
in an email or posting them on a web page, so that others actually 
download them for
personal use.  The R package, however would be considered a "derived 
work", I think,
since it contains .RData files I created and .Rd documentation.  Does 
the original
limited license apply to this?

AFAICS, none of the R licenses described at: 
http://www.r-project.org/Licenses/
seem to cover this situation, although they seem to apply to the R 
package, not the
data on which it is based.

The TeX archive CTAN defines a wider range of licenses, including a 
bunch of non-free ones,
http://ctan.mirror.rafal.ca/help/Catalogue/licenses.html

But I don't know if any of these are acceptable in R packages (e.g., 
will pass R CMD check).
I'd rather not have to consult a lawyer, so any guidance is welcome.

-- 
Michael Friendly     Email: friendly AT yorku DOT ca
Professor, Psychology Dept.
York University      Voice: 416 736-5115 x66249 Fax: 416 736-5814
4700 Keele Street    Web:   http://www.datavis.ca
Toronto, ONT  M3J 1P3 CANADA