david weaver
I'll note that!!

the first time I tried to trim the wood to brass fit with a carbon steel chisel (the fit on an infill plane), I learned a lesson on what very hard carbon steel won't tolerate (a lesson that I expected to learn), blunted the edge some and finished the job.

The next time I did the job, I'd gotten an HSS japanese chisel and it still took some damage, but about a tenth as much. Never ventured in to planing much metal after that due to the experience with the chisel, but am glad to see your responses and others and may yet make some tools to trim those transitions on infill planes without using a chisel (that type of scraping without using a plane results in ripples that need to be filed or sanded to smoothness).