It's Simplicity 5246 which is now out of print. The short strapless with the jacket looked appropriate for a semi formal and I had just enough fabric to make it work. I chose a remnant of pink metallic organza for the jacket and some super slubby pink dupioni that I've had in the stash forever for the dress. They matched perfectly.
I wasn't sure what size to cut out since I'm between sizes right now. I cut out the 12 and should have cut out the 10. It wasn't hard to take in. I used cotton for the lining and basted it to double check how the dress fit. The single biggest issue with the pattern was around the top front - I had to take the top of the princess seam in about two inches on both Princess seams. This wasn't a "I should have cut out the 10" issue but a problem with the pattern. It's easy to adjust for, just cut the angle above the breast more sharply than it is on the pattern. However, it's something to be aware of it anyone else wants to try this pattern.
I added straps for two reasons - I'm too big to get away with strapless and this photo:
Strapless just doesn't look right if you are sitting down. Ever. Plus, it was a Catholic event so...yeah, no.
Adding the straps was easy. Cut out two strips that are 3" by 15". Fold it in half and sew down the 15". Turn the strap and attach it at the seam where the back pieces and the side back pieces meet. (I undid the stitches here where the lining and the silk were joined and just flipped the dress, sewing the strap in place. This way, the only visible seam ended up being the hem) In the front, the straps go to the outside of the princess seams. I tried the dress on and marked how short the straps should be to make the dress fit appropriately.
Another change was with the hem. I'm not sure why they have the hem so terribly long but I ended up cutting 6" off in the front and just did the "hi low" thing for a hem. I'm not short (5'7") and the original hem length was only and inch or two shy of being tea length on me. To the lining, I got to use my new ruffler foot for my singer sewing machine. It was a learning curve but I finally got the hang of it and added silver tulle to the hem. Once that was attached, I flipped the edge up and sewed it down so that the tulle didn't curl under the silk and stayed down.
The jacket - I didn't make a single change to it but you can tell it looks vastly different than the pattern picture. I have no idea why.
Overall, I'm pleased with the dress. I wasn't sure at first but after getting a ton of compliments on it last night - I had ladies and gentlemen coming up to me to ask me where I got my dress- I realized it looked better on than I thought. My favorite compliment of the night was a lady who said she had been admiring my dress from afar and that it reminded her of something out of Pride and Prejudice. I'll totally own that. :-)