Thanks for your input becky_s22-appreciate that. I did finally find the model number but it was a difficult process. I looked at the bottom of the unit but the writing was so small it was impossible to read. I eventually took a photo of it and enlarge that on my iMac and was able to find the model A1378.
I had also tried the link you mentioned and had looked at it previously. The only problem with the diagram (see attached) was that the 2nd and 3rd Generation appear identical, so that was no help.
The other problem I had was thinking the numbers on the bottom row were the model number(s) so that had me confused. In the link I think it may be helpful it an arrow as pointed at the position in the microscopic writing where the Model number actually is. I hope my diagram explains what I am saying and may be helpful to others.
Thanks again for your assistance.
Regards
(maybe Apple could make the writing 2 or 3 times as big also