Need help with translation of teapot's note

[betta]

Could anyone here help with translation of this note?

Thanks in advance for your help.

[xuancheng]

Certificate

Cheng Jianming, Master craftsman, was born in Zisha town in 1962 into a family of teapot craftsman. He is the third generation 'lineage disciple' of the famous craftsman Cheng Shouqiu, and has been making teapots for 30 years.

This Duoqiu teapot is made from Dicaoqing from Huanglong mountain‘s #4 mineshaft. The craftsmanship of this item is quite fine, the lines are graceful and collectors and hobbyists will particularly like and treasure it.

Craftsman:
Cheng Jianming
(His three seals: 程建明制：made by Cheng Jianming; 程：Cheng；建明：Jianmming)
2009, Summer

[betta]

Excellent, thank you very much Xuancheng.

[antipodes]

I refer to Betta's post requesting assistance with translating a certificate of authenticity describing a teapot made by the master Cheng Jianming.
I have a teapot made by Cheng accompanied by a similar certificate.
The translation refers to three seals, to my disappointment the larger of the seals appearing on the certificate does not appear on my teapot and I want to know if I should be concerned about this omission. The underside of the pot is delineated by lines which segment the teapot's ornamentation and this may have prevented the application of the artist's chop. The omission of the chop,to my mind at least, also means it is more difficult to associate the pot with the certificate.

I would appreciate advice on the significance of the seal's omission.