I purchased a large quantity of apothecary and chemist related paraphernalia from a deceased estate down in Kent and I came across a poster in one of the lots that I just had to purchase. 

Upon returning home I noticed two handwritten messages in both the bottom left and right corners both signed off by a J.Lister which I found fascinating. 

If anyone could please provide any insight into whether these signatures may possibly be authentic or simply another individuals name; I appreciate it is difficult to determine using only photos as reference. 

New to the site, not sure how to upload photographs? Some help would beappreciated