Was able to get this spare intake/exhaust separated for riser repair without any stripped threads or broken bolts.
HF heat gun, PB Blaster, gentle persuasion, and a little patience got it done. Took a couple hours. Flapper was stuck and got it free as well. Shaft holes are enlarged, so gonna try to repair those using method described in DavidF's thread which I'll include
HEREfor ease of reference.
Planning to make shallow dremel cuts at the outside edge of flapper's middle section, as indicated in the pic below. Was sorta expecting to find rivets to drill out, but this one looks welded to me. If anyone has any tips or knows a better way of freeing flapper and shaft, I'm all ears.
