Pillbox Hat Present

You'll have to forgive me- I didn't do my hair or pose for a proper photo, but here is the pillbox hat I made from Simplicity 4178. It is red silk (reclaimed from a skirt), and the trim around the bottom is vintage and from my late grandmother's stash. I made this as a Christmas gift for a family member who will be attending a formal party in January. As I was getting ready to leave the house the other day in this frigid weather we have had lately, I realized that I do not have anything but fleece hats. Well, now the recipient has a more formal hat to go with her get up, which she has not chosen yet.

The hat is finished with lining and a grosgrain ribbon. I also attached a "Merry Christmas" tag
The hat was really pretty easy to sew, although you have to be careful because 4178 is a one size pattern. I thought the hat seemed a bit small for my head, but I have a pretty big head, to be honest. Also, it depends on whether you favor the large pillbox styles or the small style that is simply perched upon the head. I favor anything that makes my head look a bit smaller, however, the recipient does not have a big head like I do, so I think it will be a very good fit. I would like to make this pattern again for myself, but I will probably increase the hat size a bit. 

My other project that I have been working on is a button down blouse from the sixties, and I am almost done. My problem is that my machine makes a pretty lousy buttonhole (could be operator error, but I have practiced a lot), and I can't bring myself to chew up the front of the blouse with it. I would like to get an auto/one step buttonholer to use with my machine, which is a newish, basic model Brother. Can I attach a Singer buttonholer? I also have a Singer 66 I could use- are the green case buttonholers for use with straight stitch? I see tons of vintage buttonholers on eBay, but I am scared that I will buy the wrong thing, as I have already done that once. Do any of you have any tips or recommendations? Thanks in advance for your help!