What is value of 1937 silver penny?

If your Penny is a small coin of about 11 mm diameter with a crowned 1 on the reverse, it is a Maundy Penny and might fetch anything up to £20 GBP if it is in mint condition.

If it is a regular penny of 30.81 mm diameter with the seated figure of Britannia on the reverse, not much. Modified coins have little if any collector value.