First round of issues found on the 63 Valiant

First real look delving into the 63. Wife got sick (she's good now) just after we got it so it's been sitting since '07. Found a cracked exhaust manifold, bad heater core, and rust. Tried to clean the crud from the engine but it's solid crud glued to the engine. I replaced the leaking plug tube washers and checked compression with a weak starter, picked up a new one though:

1-133
2-134
3-133
4-125
5-127
6-133

Pulled valve cover and couldn't believe the crud! ...the engine runs good though. Wonder if I should just flush it for the next 25,000 oil changes.

Can someone point me to an exhaust manifold?