If your skins are a little short can you splice them to make length?

heck Okla if you use a handle wrap you don't even have to splice them. Just cover the gap with the leather, twine or what ever. I have also see on here when they were short they would use thread wraps and that looks great.

Kellys is short and he still gets er done..  

I have made just as many bows where the skins stop say 6-10" short of the tips as I have full lengthers. I wrap the ends with decorative silk thread or sinew. You can splice them, but it will be hard to hide the joint if that is a concern of yours.

With a little care you can cut and match up with no problem. I did this a few times with copper heads.

I agree.  I have only done one set of skins in my life and they are Carp but I couldn't notice the joint of the two.  Just match up the skins.  or do what pearl said and add some silk, hemp or sinew.