Sue:

there's a book on Henry Ewing that has capsule bios of Marmaduke's staff, plus some images.
As to those you list:
The generals are covered widely.
Cols. Gordon and Shave have bios in my Colonels book.
Blackwell was born in 1838, died circa 1887.
Rainwater--b. 1838, d. 1902
Ewing--b. 1840, d. 1873
Price--b. 1843, d. 1920