The tow cable along the side was actually stowed in two little, double projections of the same type as was used on the upper hull of Shermans. See the M7 Priest page on the Sherman Minutia Website, about halfway down the page of which is this photo that shows it well:
The two numbers 9 are the stowage brackets, shown in more detail in the colour picture at the top left. At the rear, the cable is held by a T-shaped bracket under the stowage bin while at the front, it’s hooked up to the right-hand towing lugs.
The above is an M7, not an M7B1, but it looks like the M7B1 was exactly the same except it had a clamp on the upper left side of the transmission housing to hold the front end of the cable, like later Shermans did as well:
NIce going! The tail light guards came out very well, but the lights themselves could be improved: The separation between the two “glass” portions should be horizontal, with the “bar” at the bottom. This bar is a slit on the prototype, with several small blackout lights behind it. The “oval” is filled with (red) glass only on the left side; on the right, there’s a piece of sheet metal with another, narrower, slit. All three slits should be painted dark - anything between gloss gray and black.
What it looks like on my M40 SPG:
Thanks for the info gentlemen. I was aware of the clips but had neither the ability nor the tools to fabricate them. So I settled for what I could happily create.
And the tail lights are tilted the way they are because that’s where the flats sat, in hindsight I could have fabricated something to render them level, but it I opted to use what I had in front of me at the time. I will attempt to paint the relevant areas of the tail lights as per @PzAufkl suggestions.
