I put my newest snapshot to ftp://nandra.iri.co.jp/pub/NetBSD/powermac/.
(your patch is applied)

The OFCONS problem is fixed.  The MACE bug may be corrected, I think.


BTW,

>* When using the `POWERMAC' kernel, the serial ports just don't work
>any more.  They seem to output, but they don't accept any input.

It may possibly cable problem.  Did you try another (null modem) cable?