Oh what shall I wear?

For the Booker Prize black tie dinner on October 14, I am toying with wearing a sea green MaxMara long dress which I've had for years but only found one occasion to wear. I have the bag, I have the shoes, but the dress is sleeveless and I must have something to cover my arms, and what shall it be?

Looking in Selfridge's all I can find are those beaded Caroline Charles jackets which I find a bit matronly. Someone suggests a shrug, which I always think look they've been designed for babies. I don't like the shrunken look. Someone else mentions a wrap, but how do you eat dinner with a shawl tied round your shoulders, and won't it just fall off? You can wind up looking like a crazy old lady with a shawl tied akimbo around your shoulders.

£695 just to cover your arms