Another interview outfit

[TheBlackKnightInYellowWellies]

I think I need a new interview outfit, I have had a few unsuccessful interviews and it feels cursed.
I don't want to change everything as I am skint. I never wear dresses, not even to get married, so please do not suggest them.
I would like to reuse my oxblood brogues and grey marl wool trousers, so am really looking for a jacket and a top or maybe even a tank top and a blouse?
I am short 16-18 and 50 ish, my arms are a problem with jackets, hence me thinking about a tank top.
Budget £100 ish
Industry is Heritage so no need to be massively smart.

I know so dull.

What I would really like is a top that has a bit of structure that works on it's own, 3/4 sleeves for preference, as long sleeves are often too long. Not too short, but not too long, a dark colour, so I don't feel like a hefalump.
An impossible dream.