Engineering Homework Help

Hi, I need help putting together a nosecone, rocket bulkheads, and coupler for a high powered rocket I am designing. I already have the nosecone and bulkheads, but I do not think they are currently the right size to fit together. The nosecone diameter is 6inches. I would like a full assembly with the nosecone and bulkheads resized to the specifications on the excel sheet, and also a fiberglass coupler put in. The bulkheads can be secured with steel u-bolts. I have attached the nosecone and bulkhead parts and the spec sheet in a zip file. There are different designs bulkheads since I did not know which design would be best.