Paul's brother Pierre died/was buried 12/16 Dec 1907 in Exeter, N.H. You might want to see if you can find his obituary and see if there's any mention of surviving family. Obtituaries often incude the names of siblings, surviving or not, and their locations. If Paul is listed as deceased, you will know that he died between 1905-1907. Otherwise, you can narrow the years down a bit and perhaps get a hint as to where he might have been found. (If course, you may have already done this.)
Pierre was a brick manufacturer in Exeter, so if Paul worked there, it may very well have been for his brother, or he may have resided with them.

Incidentally, the Eno brickyard still continues as Eno's Design Center in nearby Hampton (with offices elsewhere in NH) and now deals in tiles, stone, and flooring as well.