A genuine RAF rheostat dimmer switch.
Most prices on the Internet range from 28-33 pounds sterling on sites like Spitfire Spares. Here are Ebay quotes. [url=https://www.ebay.ie/sch/items/?_nkw=WW2+RAF+Aircraft+Dimmer+Switch+Type+K+5C+1181&_sacat=&_ex_kw=&_mPrRngCbx=1&_udlo=&_udhi=&_sop=12][/url]
Seems a bit rich. I'll consider any reasonable offer. Please inquire about shipping. Can't see the postage being over 10 euros to the furthest locale.