I have a Maillard 500 "Sealed Mechanism" 36 hole low flange rear hub in my parts bin, waiting to be laced up to a rim for use with
a 5-speed free wheel. I've cleaned and serviced this hub, so I can tell you that is uses loose bb's (not a bb cartridge) and is serviced exactly as you would any other loose bb and cone bearing hub. It seems to me to be a decent alloy hub, using standard sized bb's.

I regularly scour LBS parts bins for hubs to use for wheel builds, especially for 120mm axle spaced 5-speed stuff, and I paid $5 for this one. With a longer axle and the proper spacers, you could use it for 126mm and 6-speed cogs.