Argh what fits like medium FF

I was going to suggest Holden's Landing, they're a very similar shape to FFs and there are a fair few about, though they do tend to get snapped up quickly . Ditto for Hollow Oak.

You might find Swaddlebees a bit cheaper, and they're lovely - I loved the sized fitteds on Lili when she was a bit smaller but gave up on them when she needed to go into larges as they didn't fit quite right. The OS fitteds still fit her perfectly though.

Thanks for suggestions a few too look out for.