[texhax] Scaling math alphabets?

[Michael Barr]

I am trying to replace \cal by the Zapf chancery font, mainly because the 
latter has lower case letters and I would like to put names like Set and 
Top in this font.  However using
\DeclareMathAlphabet{\mathzc}{OT1}{pzc}{mb}{it}
followed by $\mathzc{Set}$ results in characters that are quite noticably 
smaller than the calligraphic characters.  They should scaled, probably by 
about 1200.  The Latex Companion does not appear to discuss this point.  
Is there any easy way of doing this.  I suppose I could do something like 
declaring various fonts to be pzcmi7t (which is what the .fd file loads) 
at various \magsteps and use \mathchoice to choose the correct one which 
differs according to the point size chosen, but this seems like a real 
kludge, exactly what the NFSS is supposed to obviate.  (But I have tested 
this and it works.)

Any thoughts?

Michael Barr