I just want to get your input on this (Marlin 1894 forend problem)?

OK. I have a Marlin 1894 Cowboy in .44 magnum. I have cleaned it about 20 times after I first got it about two years ago, as I rarely take it out. Well yesterday I cleaned it, and was curious as to what was behind the forend as I have never taken it off. I took the 2 screws out that are on the cap towards the muzzle end, and took the cap off and then pulled the forend off. Now it willnot go back on. The screw holes will not like up with the cap. At first I thought the wood had swollen due to the humidity so I just let it sit overnight. Upon inspection today, I found out it is not even made of wood - it is plastic. WTF. Does plastic expand like that? I really do not understand what is going wrong. I want to avoid shaving off some plastic to fit the cap back on, as I believe I should not have to do that, but I am seeing no other choice. What is your take? What do you think I should do? Bring it to a gun smith? This is the dumbest problem one could have with a ******* gun. I swear to God.