Sudbury can't accept Mayer in a trade without including an OA in the trade to the Petes or releasing an OA.......McCallum seems like the obvious choice given that his brother plays for the Petes. I'm assuming you are looking at Sam McCue's brother in London who is another OA that may be available. IMO, it will all come down to which teams are targeting Petes' players in trades and what they are offering.
Sudbury and the Soo seem like the most obvious trade partners for the Petes, but there may be some other teams who jump into the mix given the fact that there are 2 OHL entries this year and the East (where the winner could get an automatic entry to the Mem Cup) has 4 points separating the top 6 teams.
It should be an interesting TDL