Hmm, so it's the Carter pump they copied. Edelbrock, Holley and everyone else it seems sells a copy of that pump. Looks like they are all the same made in the same place but put different brand stickers on. I had fuel starvation and bough the Holley pump, when that one failed I got the Edelbrock. All three pumps where exactly the same. Same numbers on the base, same shinney finish, same everything except Holley sticker on one Edelbrock sticker on the other, I don't remember what sticker was on the third. I can't find a rebuild kit for them.

Butler sells the Carter pump, PN M6907, you could contact them as to whether they supply a rebuild kit. They also sell the Holley 12-389-11.
If I have to replace mine again I will get a Robbmc-Performance pump, PN 1006. They do repair them and may sell a rebuild kit, you could phone or email them to find out.