Since the original upload I processed the full-frame, see Version C. The animation below shows the relationship.
NGC 2442 (plus NGC 2443) is the cobra and magnitude 10.8. [Because of misclassification NGC 2443 also denotes the lower portion of NGC 2442.] It is downside up as per living in the Southern Hemisphere.  Size is only 5x3 arc minutes. It's also called the Meathook galaxy.

PGC 21457 is the mouse and magnitude 12.5. The streak within PGC 21457 is actually an edge-on background galaxy (behind PGC 21457).

PGC 100030 is magnitude 16.8.

Speaking of background galaxies, there is one visible in the lower spiral arm of NGC2442. You have to refer to the Hubble image determine which smudge it is.

Speaking of Hubble.  When fishing around for a good reference image to emulate with my data, I reviewed image thumbnails from the search results of Google. I happened to pick a Hubble image. Obviously the Hubble image at full scale has lots of detail but the image actually isn't very deep. I really liked the framing and contrast, etc. Alternatively, when you include all the faint wispy outer galaxy parts, the nonlinear stretch makes the overall scene lack contrast. The Hubble image throws most of this away (or rather it is more linear and hidden in low order bits). So I emulated this by not using a lot of depth I have in the data. When I process for depth it looks like a photograph left out in the sun, so I abandoned that path.

I stated collecting data on NGC2442 in November 2020 until February 2022. There are 23 sessions of captures over 15 months. RC10A + ASI294MM collected the luminance and Ha; and a RC8 + ASI1600MM collected the RGB channels and a second batch of Ha.  The RC10A collects 50% more photons than the RC8 and the ASI294MM has roughly 50% more quantum efficiency than the ASI1600MM.

Also the colors are correctly balanced and un-tweaked from what PhotometricColorCalibration spits back from the web. Ha data was added in the usual way to the Red channel. I found it helpful to review the standard method lucidly covered in this video.