So glad I came across this! Such a funny film, a lot like A Sunny Afternoon!
A young down-and-out British shoe salesman takes his dead uncle (a murdered casino manager) to Monte Carlo for the best time of his life - a week of fun, dancing, gambling and sun. If the young man fulfils his uncle's request, he will inherit the $6,000,000 left to him. If he doesn't, the money will go to the Universal Dog Home of Brooklyn. As Harry races around Monte Carlo with his dead uncle, guns go off, disguises go on, champagne corks pop, nightmares come to life, romance blossoms, dogs bark, and everyone sings! It's a zany, frothy, colourful and fast-paced musical with a very happy ending.