Both those names ring a bell for some reason. This is not part of my own family research (although I am a cottam...), but I posted information on sheff forum because we are trying to create a local cottam repository of knowledge. A lot of cottams originated in notts and yorks. On the Sheff forum a guy has also posted burial details for cottams in one of the cemeteries in Sheffield.
If you search for cottam on the site it should come up under a thread called 'calling all cottams', but I will find the info and post it over here.
The names you mention do ring bells - there's a lot of records left in Retford about cottams from north notts. Teresa