rigger writes:

An
"experienced" scraper hand could easily do the horizontal knee surfaces
in less than a day (after the vertical surfaces of course) ,with the
proper tools.

Ten, count em, 10 surfaces to be scraped on that one axis alone. Flat,
bearing quality, aligned up/down, tilt fore/aft, tilt left/right, all to
better than 0.001", with the concave wear something like 0.010 in the
extreme.

Assuming you disassembled, cleaned and shipped (both ways) out to an
expensive grind job, the hand scraping would still be days of work. If
you're removing the meat by scraping alone, then it is easily weeks of
backbreaking labor.