1803 Ein Volles Glas Des Gastes Spass

1803 Ein Volles Glas Des Gastes Spass - meaning in German ...."When the glass is filled the guests are thrilled". 

This is what I know of it.......... - This Stein was handed down to me and I was told it was from my grandfather and was given to him by his father. I took this to a dealer who told me that it's very special and unique due to the stamping on the bottom which most of them do not have. He was unsure what it meant or means or what it's even worth. He told me that the date stamp inside of the handle is when it was made which is 1803. He told me that it's handcrafted, hand painted, and also a unique design. He told me most of the steins by Gertz do not have a signature and a certain mark in which this one does. He offered $1000.00 but hes a collector with a pawn shop which indicates to me it's probably worth more than $1000.00.    This is all that I know of this matter and I do wish to sell it