Pattern Drafting Bodice (Attempt 1) Part 2

Today I have been putting my bodice pattern block to use and testing it works. I've marked out the shape onto calico and cut it out with a centimeter seem allowance for me to stitch it together. I've sewn the darts first to get the shape and tested it on a mannequin to see how it's shaped and whether it fits. The neckline and armholes look a little tight but it fits. My only problem is that if I sew to fully together how will I fit it on to the mannequin again as the the waist of the garment won't fit over the chest. I need to devise a way for it to come undone so I can take it on and off. I'm thinking possibly a zip but I believe they are complicated to apply to clothing. I may have to think of some fast alternatives. This is something that I may need to consider when finishing a garment. Also in future while drafting where I could apply the fixing.