McDavid
Seasons/Games: 7 / 487
Hart: 1, 1, 2, 3, 5, 5
AS Center: 1, 1, 1, 1, 2, 3
Points: 1, 1, 1, 1, 2, 2
Goals: 2, 6, 6, 7, 10
Assists: 1, 1, 2, 2, 2, 3
Selke: no top-5
Cups: none
Smythe: none
International: Has never had the opportunity to play in an Olympics. Has performed well in successful lower-level international tourneys.
A decent comparable is Mikita at #24:
Mikita
Seasons/Games: 22/1396
Hart: 1, 1, 2, 4, 5, 6, 7
AS Center: 1, 1, 1, 1, 1, 1, 2, 2, 6
Points: 1, 1, 1, 1, 2, 3, 3, 3, 4
Goals: 2, 2, 2, 3, 4, 5, 6
Assists: 1, 1, 1, 2, 2, 2, 4, 5, 7, 8
Selke: Played in a time before the Selke, but was generally considered decent defensively.
Cups: 1
Smythe: none
International: Had 1 assist in 2 games in the 1972 Summit Series, which occurred after he turned 30... so it's probably barely worth mentioning. (Then again, Hull led the 1974 Summit Series in scoring at age 35... so maybe it is worth mentioning?)
There are a couple of other parallels between Mikita and McDavid. Both had teammates who largely played on different lines at even strength but were still able to compete with them in terms of points production (but were better goal-scorers). Each led one postseason in scoring and plus-minus without winning the Cup.
At this point, Mikita is ahead due to the fact that he finished his career (and had more years to accumulate more significant seasons), and McDavid is still only 25.
So I'd guess McDavid at somewhere between 30-50... for now.