I searched and searched for a photo of the bottom of the Librem 14, and I could not find one anywhere. 
I finally found out how many screws are on the bottom from @nicole.faerber 's 2021-04-08 blog post: 9.
My Librem15v4 has 15 [corrected: 14] screws of at least 2 lengths, and the Librem 13v3 &13v4 have 12 screws of 2 different lengths. It is a very nice improvement for the L14 to have only 9 screws, all the same length. Bravo!