In the 110610 MMD David Dunn asks for recommendations on the proper
weight of piano hammers he should use in restoring a Recordo piano.

Well, he should start with some reading, sources like these:

    http://www.bluebookofpianos.com/hammers.htm 

And then find an experienced piano technician.

If you want to have the old hammers refelted, the question is obsolete,
since you will get your hammers back like new, with the (more or less)
original weight.

If you want to use new hammers the question is also more or less
obsolete.  Your supplier will give you a standard set of hammers.
If there is a choice, it will be in quality (and price!).

Since you are bound to the size, type, and dimensions of the old
hammers, I think you will not have much to worry about the weight.

Jan Kijlstra