I have a candlestick connected to a 300K magneto ringer box that appears to have 20AL stamped on the back of the perch but scratched out. On the side is stamped a small 40AL with a large 1 stamped in front of the 40. I have read about 40AL phones converted to 140AL, but not from a 20AL. The base has a 1904 patent date as the latest date. Just curious about the history of this phone if anyone has any info.
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I wouldn't have thought it was possible to convert a 20 AL to a 40 AL. I think it is probably a refurbished 20 AL but in the process it gained a re-cycled perch originally used on a 40 AL.
The conversion to AST is straight forward but usually from 20 to 120AL and 40 to 140AL
Regards
Jack