Oh an the P3 is a bit smaller than the P4 the P4 is 2.5 inches tall overall, the blanks however should fit in both of them.
You should ask Patrick from Commando Lock if he can maybe forward you 1-2 blanks because the also fit in nicely.
If you have any problems just let me know, my locksmith should have the RH6 in stock and since I still got your address I could send that out to you by the End of the week, would be there 5-10 days later then :8):
Adrian