Replacing springs, will CJ5 ones work?

In searching around the trailer section I found this link:
http://vegasauto.net/m416/m416faq.html

which lists the springs for a 416 trailer as being:
Springs:
1950's vintage CJ3A/CJ3B FRONT leaf springs (36.25x1.75 inch leaf springs)

My question:

Since I'll have to re-weld spring mounts anyway from the not-original location they're currently in, should I have problems using my original early (59) CJ 5 Springs?
Currently, the trailer has extremely rigid monoleafs which must've been installed for hauling something ungodly heavy. As such it bounces all the time even with 10 psi in the tires.

 

I don't see any problems if you're relocating the mounts anyway
should work

 

I know that 10 leaf front springs for the CJ-2A through CJ-3B work, and I've read that early CJ-5 fronts springs are the same but don't have personal experience with those.

But replacement springs are relatively inexpensive, why use 48 year old springs from your CJ-5 when you can get new ones that don't sag?

 

Well, I'd like to try the old CJ5 springs becuase they appear to be in very good shape and are lying uselessly in my shop, along with replacement NAPA shocks with about 10 farm miles on them.

I suppose I have a secondary question: Are the measurements on the front springs for the CJ-2A -CJ-3B the same as the CJ-5 front springs? If so, i could easily upgrade to new springs using my new welded mounts if I'm unhappy with my old CJ-5 springs.

 

They are supposed to be, but I don't know for sure. One way to find out (assuming that no one here knows the length and width of early CJ-5 front springs) is to see if the front springs for the CJ-2A through CJ-3B have the same part number as the CJ-5 front springs at Walck's 4WD and other Internet jeep parts vendors.