RARE Luftschutz steel belt buckle by R.S.&S.

Very desirable and seldom seen belt buckle for air-raid protection 'Luftschutz'. Steel construction with silver finish, nearly 95% intact. Maker marked on the reverse by R.S.&S. (Richard Sieper & Söhne). This is actually only the second time I have a rare buckle like this for sale on the website!