1930 Deforest Crosley

looking for info on early Deforest Crosley Trirdyn battery set. How does one date these early sets it doesn’t have a model number or name as per say, there is a number on inside of front C1837R.The unit looks similar to the American Crosley 3R3 trirdyn.As usual the inter-stage transformers were open circuit,missing on off switch,but plays quite well now.It also has the EZ toon dial knobs which the American Crosleys didn’t have. Can add a picture if anyone is intewrested.
Martin VE4AAM