Hi,
We will need more information. That is a relatively common tube line up for a radio built in the early to mid 1930's.
Best Regards,
Bill Grimm
The schematic for Sparton 61 is at the following url:
http://www.nostalgiaair.org/PagesByModel/844/M0018844.pdf
It says it was manufactured by the Sparks-Withington Co.
I hope this is what you are looking for.
Doug