I have just purchased a new to me procraft 88 with a evinrude XP150. For what ever reason the tag plate is missing. I heard you can use the freeze plug number to find it. Can anyone tell me Any other way. If there is one.  And is this the freeze plug? 

Your title should give you all of the pertinent info.

I don't remember if VA (I was stationed there back in the 80's) ,required a title for the motor but I don't think they did, if so, it should have the model number and then it's easy to tell.

That's not a freeze plug, it's just an aluminum disk stuck in a recess in the block to hold it with the serial number on it.  Later they started putting put the model also.  

I don't know how you can tell just from the serial number.  The model number is the one that has the size, year and type.

Sometimes you can look around at some of the different parts that might have a manufacture date on them.  A lot of times the power pack and the starter if they are still the original.