After some checking around, I believe I've found an answer. I talked to a guy (Machinst)who makes crank scrapers for many different engines. He has been dealing with these engines for a quite awhile. In his opinion, I should be okay without that Windage tray. Mainly Because, my pan has another built in tray towards the bottom.
Thanks for the help. Still if there is anyone, who has ever had this problem (no windage tray mounts) I would like to hear about it. It seems to be, that mine is the only documented case of missing the mounts.