The only surviving Class 503 ‘Wirral’ EMU was at the Electric Railway Museum in Coventry but that closed not so long ago meaning the rolling stock in the care of that museum had to found new homes. Merseyrail’s Class 503 now has a home at the former Hornby Factory in Margate of all places. The link below has the story :-
Quote from the article linked above:- The Class 503 trains were built in two batches. The first batch was built in 1938 by Met-Cam and BRC&W Co., their use was on the newly electrified route between Liverpool Central and the Wirral Peninsular or Rock Ferry via the Mersey Railway but run by the LMS. The second batch was built in 1956 to replace the original Mersey Railway stock. The one preserved today is from the earlier LMS stock, all were withdrawn from traffic in 1985.