If it makes the decision easier for you I own Penny's only 1994/95 alternate blue game used jersey that he wore for the regular season, playoffs and Finals and it's a 50 +4. I also know where the white shirt from that season is, again worn through regular season and Finals and that is also a 50 +4. Penny did wear 46 +3 as a rookie but made the switch in 1994/95. I'd say that shirt is a pro cut (it's original and legit but not game used) and I'd agree that the sig looks dubious at best.
Hope that helps.