Bought both from an Ebay vendor: scalecitydesigns. Here is a link to the gratings:
https://www.ebay.com/itm/48-653-Sewer-drain-grates-catch-basin-by-curb-O-Scale-FKA-Keil-Line-/323283585080?_trksid=p2349624.m46890.l49292
and to the manhole covers:
https://www.ebay.com/itm/1-48-1-43-O-scale-laser-cut-sewer-caps-manhole-covers-CUSTOM-ENGRAVED-ANY-NAME-/221662032599?_trksid=p2349624.m46890.l49292