That's a great find. I love my RA-103. This article has some notes that may be interesting:
http://antiqueradio.org/DuMontRA-103Television.htm
Since yours already shows signs of life, that should be a straightforward restoration. Just follow the Hippocratic motto: Above all, do no harm
Regards,
Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html