Information on Ernemann plate cameras

I am trying to obtain information on a faily 'heirloom' - i.e.
Ernemann of Dresden 4.75 in Beck-Neostigman f.6 camera, presumably
plate (1/4 ?) sold to our family prior 1939, maybe as early as mid
1920's, unknown cost, by Messrs Sands Hunter of Strand, London, WC2.

Any information as to this model would be appreciated. Unfortunately,
the "concertina" on the viewing plate is falling apart - can one
obtain a replacement, and can one still obtain appropriate plates and
from whom/where.

Thanks.