I have Aluminum windows that have the name Milco on them and I need 3 replacement parts that I am hoping I can find online. The 3 pictures have arrows showing what I need. In the first picture the plastic piece has splintered and falls out and needs to be replaced. I think that is what the single hung bottom piece slides up and down on. Sorry for not knowing the names of the parts, I'm a computer guy not a window guy. I'm hoping it's just a matter of sliding a new plastic piece in there and snapping it in place. The second thing I need is the plastic piece that screws in along the top of the window and is arched. The plastic piece is cracked where the screws go in on either corner. The 3rd thing I need is the white plastic piece that goes over top of the metal piece in the picture that acts as another locking mechanism. I'm hoping someone can point me to a site online where I could order all 3 parts and have them delivered. Thanks ahead of time for any info.