To ask for help with a ww2 costume

[twinkletoedelephant]

Am looking for a ww2 British soldier outfit to fit child who wears age 13
I can only find one for 10-12. They won't fit
The local Army surplus store is really expensive for something that is only going to be worn once.
Will spend up to £30
Any ideas would be greatly appreciated.

m.ebay.co.uk/itm/Kids-1940s-WW2-Army-Officer-Uniform-Boys-Book-Week-Fancy-Dress-Childs-Costume-/131420717334?nav=SEARCH any good?

Sorry just seen the sizes and read properly.

m.ebay.co.uk/itm/Child-Army-Officer-Costume-Boys-WW1-Army-Uniform-Fancy-Dress-Outfit-New-/181790258492?nav=SEARCH

Would a cut down boiler suit, be any good to go over a shirt/tie?

I remember trying to find one for my tall son and it turned out impossible. In the end he went as a refugee, shirt and v neck sleeveless jumper, cut off school trousers, flat cap and a gas mask box.

kids boiler suits

I have checked all the eBay ones xl is only 10-12 and won't fit and u can't find a small man size.
Will look in boiler suit.
Have covered a washing powder box in brown paper for a gas mask box.
It's a school thing si mist children will be refugees. Child never follows the crowd