Older home, 1920s, don’t see a lot of homes this age and I am not sure of the siding material? - Fiber Cement? Any asbestos content?
It certainly could be an acm, I would write it up as such. The only way to know for sure is to have it tested. If it’s left alone and in a non-friable state then it shouldn’t be a problem…
Looks a little fresh to be original ACM siding. They do make standard fiber cement replacement shingles for that type of siding.
You can actually still by the asbestos stock on E-bay.
http://www.ebay.com/itm/like/151399288753?lpid=82&chn=ps
Gaf makes 3 replicas here to match the most common that I installed up here as a kid with the old man. Best siding one good buy. 
http://www.gaf-weatherside.com/?gclid=CLqlzpbgl8YCFUqRHwod3ywAnQ
The Ebay ad is for a replica too.
Thanks for the input. Much appreciated.