The Freescale MC68040FE33A is now installed. It's so much easier to solder a QFP with clean and straight pins.
It's still not showing up as a full 68040 with an FPU. The part datasheet says it has one: http://www.nxp.com/webapp/search.partparamdetail.framework?PART_NUMBER=MC68040FE33A
I noticed on installing this CPU I needed to do a PRAM reset before it would boot. Hmm.
I dunno... I'll get it on my network and try to find a more through system diagnosis/benchmarking tool than System Profiler.