Help To Identify Chinese Stamps Please

I am working my way through my Dad's pretty extensive, but very disorganised stamp collection. I have managed to identify most of the Chinese stamps from Google and reverse image searching, but have been unable to get anywhere with these two identical stamps. From the central image and some auto-translation, I think they may be telegraph/telegram stamps (if there is such a thing), but can anyone confirm? Many thanks.

Scott 1153-1156 Inclusive 1956 ROC

Commemorative 51 75th Anniversary of Telegraph Service Commemorative Issue (1956)
https://www.post.gov.tw/post/intern...le_name=B051

Stamp SN B051
Stamp Name Commemorative 51 75th Anniversary of Telegraph Service Commemorative Issue (1956)
Stamp Cat Standard Commemorative Stamps
Stamp Cat Post && Telecommunications, Emblems, Organizations
Issue date 1956-12-28
Suspersion date 1961-12-16
Dimension of stamps(mm.) 26 x 34
Size of souvenir Sheet (mm.)
Printer China Engraving & Printing Works, R.O.C.
Drawer
Designer Liao Wei-lin
Photographer
Engraver Pao Liang-yu
Creative Director
Sheet composition (10×5)×2
Print color
Process Intaglio
Paper 63-lb watermarked superior stamp printing paper<br>
Back Gumless
Perforation 12

New to forum, and amazed at the wealth of knowledge like ROD222's post that gave such detail of these very obscure (to me) stamps.