The most I've done was to carry along a large wooden drawer-pull knob, with the hole very slightly enlarged, to use as a "palm saver." I made up some extra-length wooden rods in 7/16" diameter for my .58 and 1/2" diameter for my .69's, with threaded tips fitted and cross-pinned. I use these for cleaning.
Dixie used to offer ramrod adapters which would allow using 5/16"-27 shotgun brushes and mops on the various steel rods, but last time I checked, they only had one size left in stock.
However, on some of the steel ramrods on the Italian guns, the swelled end is said to be a separate piece just pressed or crimped in on. The joint may be nearly invisible, but they are in two pieces. These are fine for loading, which is just pushing against resistance, but for cleaning or removing a dry ball, which involves pulling against resistance, these have been known to pull apart! Somebody who advertised in Muzzle Blasts a while back was offering one-piece forged rods for the Brown Bess, which would be great, and probably more authentic, but I haven't noticed whether these are still available or not.
I also bought two solid aluminum rods with wood handles, nylon muzzle protectors, and brass jag tips from S&S Firearms. These can be used for loading, or for running cleaning patches up and down the bore. However, the threaded ends of the jags on these are 5/16"-24. Shotgun cleaning accessories are threaded 5/16"-27, and in fact, the breech face scrapers I bought from S&S were also 5/16"-27, so these rods are only good for loading or pushing patches.
As far as actually replacing or modifying the original military-style steel ros, though, I never have.
Best regards,
Notchy Bob
