Melt butter in saucepan; stir in flour, salt and paprika, blending well.
Slowly stir in milk, stirring until smooth.
Stir a bit of the warm mixture into egg yolks.
Add egg yolks, sherry, and Worcestershire sauce, along with mushrooms, chopped onion, and flaked crab meat.
Place in a 1 1/2-quart casserole.
Cut hard-boiled eggs in halves; remove yolks.
Mash yolks and mix with a little mayonnaise.
Refill egg halves and place on top of the casserole.
Heat for about 15-20 minutes in a 350° oven.
A little crab meat can be used on top of deviled eggs.
This can be made in advance and refrigerated until time to pop into the oven