The guru of all this notts cottam info is a lady known as mrs C, who I can put you in touch with if you like. I'll post on here a copy of what I posted at Sheff Forum to make it easier. I checked the thread though and it is still going, but you are right for some reason isn't coming up when searched for - probably a coding problem.
For cottam research about notts cottams, Mrs C recommends trying the following:
Bassetlaw Museum website, which now includes the Welchman Collection of photos. There are cottam photos there, including Thomas Cottam and more recent cottams. You need to click on people and then scroll down to cottam. (www.bassetlawmuseum.org.uk)
IGI at Retford's Denman Library, which includes records of many of north notts cottams. The index includes cottams that go back to seventeenth century from Retford and surrounding villages.
Examples of these follow on the next post. Use these as a guide, but check the records yourself if the person you are looking for is not there - or drop a line and I'll see if I can get someone to check for you if you don't live locally.