From "Rails Beyond the Rutland" (dated 1988), here was the GMRC roster:
305...Alco S-4.....Blt 1950 .... Ex D&H No 3050, acquired 1969
400...Alco RS-1...Blt 1948..... Ex-IT No 753, 1053, ex-GMO 1053, acqu '76
401...Alco RS-1...Blt 1950..... Ex-IT No 756, 1056, ex-GMO 1056, acqu '76
405...Alco RS-1...Blt 1951..... Ex-Rutland No 405, acquired April 1965
1849.EMD GP9....Blt 1955..... Ex-NP No 223, ex BN No 1949, acqu 1984
1850.EMD GP9....Blt 19--...... Ex-C&O No 8161, acqu Sept 1987
More detailed reference on the S-4 (s)
303 - S-4 ... Ex-D&H 3036 ... Acquired 5/66 ... Went to NEGS after traded in 1983 for GP-9 #1849
305 - S-4 ... Ex-D&H 3050, (leased to Bombardier as of book writing)
Ex-D&H 3026, bought as parts source, cut up for scrap
Vermont Railway over the years has also owned several RS-1s (5, of which 2 of Rutland heritage), plus 6 RS-3s and other motive power, none of which remains on the roster today.
Hope this info helps.
-JH