UP Cabooses

[kwk100]

Hi Everybody!

I just picked up the newest issue of Model Railroading, and on page 19 there is an ad for Overland Models. They are selling two different Union Pacific Cabooses. One is a CA-11 and the other is a CA-11 Modified. I was wondering what the difference is between these two, from the photos of the models it looks like it must be internal but I am not sure?

Thanks

This is kwk100, and I'm 10-10 on the side

http://www.hankstruckpictures.com/pix/trucks/david_miller/dm_kw_k100_vit_indianapolis_sml.jpg
David E Miller Collection: www.hankstruckpictures.com/trucks.htm