IMO the chain mounts don't have to be perfectly located.
A -slight- tilt when the WD bars are installed is probably
I moved my LP tank mount.
It was tack welded on there and I simply ground off the
welds and removed my battery box angle iron as well.
I ground off the weld splatter and painted all the tongue
with black rustoleum.
I then re-installed my LP tray and the battery box angle
iron with self tapping 1/4" hex head bolts.
Drill the correct size hole and use a little oil on the threads
when you install the bolts or you might snap one off.
You can get these at Home Depot or Lowes in the hardware
isle. They have "drill" points but it's much easier if you
drill your holes with a normal drill bit first.
If you've got access to a little 4" disk grinder and a drill
motor you can do this in a half day not counting time
for the paint to dry.
It was a 2 beer job for me but I've been an industrial
maintenance guy for 37 years and a home DIYer for
longer than that.
I actually swapped my LP tray and battery box locations.
From the factory they had the batteries behind the LP
tanks. I thought that left the LP out front looking kinda
funny. I put my LP tanks in the rear as close to the front
skin on the trailer as I could and still be able to get the
plastic LP cover on and off. Then the battery box angle
irons went in front of that and the chain hangers fit
in between the LP tray and the batteries.
My chains are pretty straight when the WD bars are installed and we're hitched.
It worked for me. You can measure yours and see
if you think it will work for you.
I can take a picture if that would help but your tongue
might be a different length so just because it fit on
my trailer doesn't mean you can do it for sure.