Went into my local charity shop for a browse, and managed to grab 2 pairs of Next Petites BNWT trousers in my size - £8 for both.
next charity shop - a Powerrangers top BNWT - £1 - he's thrilled.
But just to rebalance my karma, I bought some new sole grips for my boots and they must have fallen out of the pushchair on the way home