hmv-97c manufacturing period?

i am about to complete the restoration of my black leather hmv-97c but i haven't found any detailed information of this machine on the internet. does anyone know the manufacturing period of this machines? when did it start and finish? if anyone wants i can post the serial number of my 97c. and finally can anyone recommend me a book about hmv acoustic phonographs, including 97c?

I accidently deleted a response I made last week. I'm not sure if you saw it.

In any event, according to David Cooper's 'The Perfect Portable' which devotes several pages to the model 97, it it was in production from 1934 to about 1960, and was sold as a less costly alternative to the 102 portable. He does not provide a mfg. dating guide, but does state that the 97C was available in 1939.

I realize that this is not much to go on.

it is not important, i got the message, the period. 97c appeared in 1939. i wish i had got the perfect date according to the serial number. thanks.

Unlike the Victor Talking Machine Co, HMV didn't keep the serial no. to year information like victor in the U.S. I don't think HMV even used serial numbers much before about 1928. Even Edison, who used serial numbers on his machines pretty much from the start, didn't keep this information, or if he did, nobody's found it yet.
The only other company I've found such accurate info, is The Singer Sewing Machine Company.
I've got a 97b, as well as a few other HMVs and would love to find out the exact year they were made, but unless this info is discovered in someones basement in the future, Im afraid it just ain't possible!

Serial numbers were not used for quality-control until after World War II. They were originally wanted by law enforcement in several states to identify stolen property.