Yea, Leaf didn't cover much of what you'd need
http://www.baseball-reference.com/teams/CLE/1948.shtml
That's your template...Most of them are easy-ish to come by through later Topps, Bowman and the 1948 Leaf. Beckett breaks down most of them easy enough. Rest can be messy...here are the harder ones
Don Black - 1948 Blue Tint (Or Late 40s Indians Team Issues)
Ernie Groth - 1950 Remar Bread
Lyman Linde 1949 Hage's Dairy (Hardest card in the set)
Les Webber 1942,43 and 46 Dodgers Team Issue (There is no option on Webber smaller than 8x10 unless you count the 1970s reprint)
Butch Wensloff 1944 Yankee Stamps (Also an option for 1947 Tip Top but Wensloff might be the hardest card in the whole set)
Russ Christopher 1950 Hage's Dairy (Many 40s team issues, probably the better bet)
Ed Klieman Late 40s Indians Team Issue (Or 47 Van Patrick)
If you're going to go for the full set, good luck