Sun Distributor 504 Tester Repair

Hi, I have recently acquired a Sun Distributor Tester, the 504 model. The tester seems to be working okay but I do need to repair the dwell meter and the condenser tester seems to be a bit off. Does anyone out there have any experience with this type of tester and/or have a repair manual they can share? I love the tester and would like to get it fully functioning without having to use a seperate tester to read dwell when testing distributors. Thanks!

 

Don't have any manuals but I did save this lnk from another post.

http://paramountd.com/index.html

 

Thanks for the link.