Form altering question

I am going to be mounting a year and a half old cow elk. As you know cow forms are very limited, especially in size. I have done alterations for turns and such but this will be my biggest alteration project. I am going to have to take at least two inches off the neck and going to have to narrow the head and shoulders. I think it would be better to cut and remove foam from the inside and foam back together instead of trying to rasp down to the size I need.
Am I correct in this thinking?

Thanks,
Dave

 

Tanglewood,
I did not notice the spike from from research. I think it may work. I have got a 9.5" e-n and 17.5" neck. That spike form is 10.5" e-n and 18.5" neck. That would be a lot easier to modify.

Thanks for your input.

Just noticed that the cow form from research is the same size.

 

I have already ordered a form from Jonas. This is the one I ordered.

http://www.jonas-supply.com/_e/Elk/product/3-8594/Elk_Cow_10_x_17_x_22_LT_Signature_Series.htm

I have not got it yet, but was thinking the 17" measurement was a neck measurement. That would have worked great. However, after looking at there how to measure section, I am wondering if that is the nose to the back of head measurement and it has a 22" neck. If so, it is going to be way big.

 

Well, I got the form and the 17" measurement was from the nose to the back of the head. The neck tight behind the ears is 23". I got another cow I can use this form on. I will have to go with something different for the other one though.