Yes, I should have mentioned that. I only have playoff data back to 1926-27.
I made a lazy attempt at calculating Nighbor's placements, using hockey-reference from 1918 and newspaper articles for the earlier playoffs. I think these might be missing a few games from the intra-league playoffs, but at least we have a rough comparison.
MOST TIMES LEADING TEAM IN GOALS IN PLAYOFFS
Player | Times
Joe Sakic* | 7
Mario Lemieux* | 6
Mike Bossy* | 6
Peter Forsberg* | 5
Bernie Geoffrion* | 4
Guy Lafleur* | 4
Bryan Trottier* | 3
Red Kelly* | 3
Frank Nighbor | 1
Bobby Orr* | 1
Paul Coffey* | 1
Nicklas Lidstrom* | 1
Henri Richard* | 0
Larry Robinson* | 0
MOST TIMES LEADING TEAM IN ASSISTS IN PLAYOFFS
Player | Times
Peter Forsberg* | 6
Frank Nighbor | 6
Guy Lafleur* | 5
Nicklas Lidstrom* | 5
Bryan Trottier* | 5
Bobby Orr* | 4
Larry Robinson* | 4
Mario Lemieux* | 3
Joe Sakic* | 3
Red Kelly* | 3
Mike Bossy* | 3
Bernie Geoffrion* | 2
Paul Coffey* | 2
Henri Richard* | 1
MOST TIMES LEADING TEAM IN POINTS IN PLAYOFFS
Player | Times
Joe Sakic* | 8
Mario Lemieux* | 7
Guy Lafleur* | 7
Peter Forsberg* | 6
Bernie Geoffrion* | 4
Frank Nighbor | 3
Bobby Orr* | 3
Bryan Trottier* | 3
Mike Bossy* | 3
Red Kelly* | 2
Nicklas Lidstrom* | 2
Larry Robinson* | 2
Henri Richard* | 2
Paul Coffey* | 2
MOST TIMES PLACING IN TOP FIVE IN PLAYOFFS - GOALS
Player|1st|2nd|3rd|4th|5th|Total
Bernie Geoffrion* | 2 | 1 | 1 | 2 | 2 | 8
Guy Lafleur* | 2 | 1 | 2 | | | 5
Mike Bossy* | 3 | | 1 | | | 4
Mario Lemieux* | 1 | 2 | | 1 | | 4
Joe Sakic* | 2 | 1 | | | | 3
Frank Nighbor | 1 | 1 | 1 | | | 3
Peter Forsberg* | | 1 | | 1 | 1 | 3
Henri Richard* | | | 1 | 1 | 1 | 3
Bryan Trottier* | 1 | | | 1 | | 2
Red Kelly* | | 1 | | 1 | | 2
Paul Coffey* | | | 1 | | | 1
Bobby Orr* | | | 1 | | | 1
Larry Robinson* | | | | | | 0
Nicklas Lidstrom* | | | | | | 0
MOST TIMES PLACING IN TOP FIVE IN PLAYOFFS - ASSISTS
Player|1st|2nd|3rd|4th|5th|Total
Frank Nighbor | 3 | 2 | | 1 | 1 | 7
Bernie Geoffrion* | 1 | 2 | 1 | 1 | | 5
Guy Lafleur* | 2 | 1 | | 1 | | 4
Bobby Orr* | 2 | | | 2 | | 4
Joe Sakic* | 1 | 1 | 1 | 1 | | 4
Larry Robinson* | 1 | | 2 | | 1 | 4
Bryan Trottier* | 2 | 1 | | | | 3
Mario Lemieux* | 1 | 2 | | | | 3
Peter Forsberg* | 1 | 1 | | | 1 | 3
Henri Richard* | | 1 | 1 | | 1 | 3
Paul Coffey* | | 1 | 1 | | 1 | 3
Red Kelly* | | | 1 | 2 | | 3
Mike Bossy* | 1 | | 1 | | | 2
Nicklas Lidstrom* | | 1 | 1 | | | 2
MOST TIMES PLACING IN TOP FIVE IN PLAYOFFS - POINTS
Player|1st|2nd|3rd|4th|5th|Total
Bernie Geoffrion* | 2 | 3 | 1 | 1 | | 7
Guy Lafleur* | 3 | 1 | 1 | | | 5
Frank Nighbor | 3 | | 2 | | | 5
Joe Sakic* | 2 | 1 | 1 | 1 | | 5
Mike Bossy* | 1 | 2 | | | 1 | 4
Bryan Trottier* | 2 | 1 | | | | 3
Mario Lemieux* | 2 | 1 | | | | 3
Peter Forsberg* | 2 | | | | 1 | 3
Bobby Orr* | 1 | 1 | 1 | | | 3
Henri Richard* | 1 | | | | 2 | 3
Paul Coffey* | | 1 | | 1 | 1 | 3
Nicklas Lidstrom* | | | 1 | 1 | | 2
Red Kelly* | | | 1 | 1 | | 2
Larry Robinson* | 1 | | | | | 1