Don Hutson 6'1" 183
Jerry Rice 6'2" 200
Greg Jennings 5'11" 195
Reggie Wayne 6'0" 198
Hutson may have been a few pounds light, but he didn't have the work out regimen they have now. There are WRs in the league doing very well now that are as light.
Hutson ran the 100 yd dash in 9.8 seconds. Which is less than .8 seconds slower than the 2010 world record. If he was less than .4 seconds slower than the current world record in the 40 yard dash, he would be under 4.6 in the 40. Jerry Rice ran a 4.71.
I don't think there is anything in the modern NFL that Hutson would be unable to do. He did everything modern receivers do now with poorer equipment, no domes, no facemask and rules that didn't stop DBs from assaulting him all the way down the field. He was double and triple teamed for entire games. Hutson invented the WR position by introducing routes. Taking the team beyond the Knute Rockne Box Offence.
The medical treatment of injuries alone would knock most modern players out of the game within their first couple years. Or even in college. A torn knee was a death sentence for an NFL player in the 30s and 40s.
I want to go out like my Grandpa did. Peacefully in his sleep.
Not screaming in terror like his passengers.