, used with "(MOMBASA)/MR 4/91" single circle datestamp; fine, from the foot of the sheet. R.P.S. Certificate (1963), Friedl Certificate (1983). S.G. 21, £1,300. Photo" /> used 1 Anna on 4 annas, initialled<I> "A.B."</I>, used with "(MOMBASA)/MR 4/91" single circle datestamp; fine, from the foot of the sheet. R.P.S. Certificate (1963), Friedl Certificate (1983). S.G. 21, £1,300. Photo | Christie's