A simple Google search for "haute-marne archives" turned up a link to the "Etat civil" (state civil records).

That takes you to a page listing the collections. They are listed by village, like A-Ch, Ch-J, L-Pu, and R-W. For some reason they have two sets -- one for the department and one for the commune.

For Pierrefaites we'd use the one included in the villages of Lachapelle-en-Blaisy to Puits-des-Mèzes. A list of villages appears. Click on Pierrefaites. Click on the date range - in this case 1832-1847. (you've done all the difficult work so this search is relatively easy). To save you the trouble of clicking through each image, check pages 43 or 54 depending on the collection.

I don't read French, but I think I can make out the important bits. It says Francois Pierrot was the widower of Marguerite Courtejoie. I believe it also says he was 77 and the son of Etienne Pierrot and Francoise Naisin. So his birth was about 1758. At that time, records were in Latin (throwing up hands). http://www.actes52.fr doesn't APPEAR to have all of those records translated yet.