I did it! Against my natural inclinations, I dug deep and found the patience to remake and replace the sleeves of my denim Tova top. If you look back at the original photos, you'd be more than forgiven for not being able to spot any difference! But although the change is very subtle, I'm glad that I did. The sleeves initially felt a tiny bit tight when I raised my arms. I love everything else about this garment, and can see it being part of my wardrobe for years, if not decades, so I didn't want there to be any element that would make me avoid wearing it.
So what did I do? Well I begun by following the steps in this tutorial (thanks Claire for directing me to it), slash-and-flaring the pattern piece out, inserting some paper behind and adding 3cm across the width of the sleeve (see below). By spreading out the sleeve piece in this fashion, you unavoidably monkey about with the sleeve head, making it shallower. The tutorial would have you trace and then retain the height and shape of the original sleeve-head, however I chose not to because A) adding only a small amount to the width like I did didn't change the sleeve head very much and B) the original Tova pattern piece sleeve head was crazy-high and I always felt it was a little unnecessary (not that I know what problem a tall sleeve head might cause!). Because I used the altered rather than original sleeve head, I didn't need to follow step 4, making the armhole larger using one of two approaches. I didn't feel the size of the armhole needed adjusting, and in fact I was concerned that by doing so might start making this top start look looser and potentially lose some of the delicate proportions that makes this pattern so appealing.
I'm not sure how much more use I'll get from this top during my pregnancy because my boobs may expand even more than they already have (heavens!), and as you can see in the top two pictures, it's already getting a little tight! But I'm very happy that, having made the effort now, when things calm down in the bust area, this top is ready to be reached for as a useful breast-feeding friendly option. It feels good to resist instant gratification sometimes and pay yourself forward, doesn't it?!