Aromat: JS1E-12V and NTE: R46-5D3-12 should git ya started. Mouser.com, digikey.com, newark.com are popular online suppliers
Drill out the heat set rivet heads on the back of the J-box, I think there's five. Just the heads, don't drill into the J-box itself! Remove all fuses, remove the back cover, remove the one phillips head screw, slip the board out. Check for cracked solder joints, and traces, reflow if needed.
Assembly is the reverse, except no real need to weld the back cover back on. The rubber strap will be sufficient.
[edit] George Young has some nice write-ups on his website. Check the Wiki/FAQ section, and
http://web.ncf.ca/ag136/jBoxDiagnosis.htm to get ya started.
[end edit]
Rick