I picked up a 1994 5.2 4X4 auto tranny 76000 miles. Wanted to change all the fluid & filter.
Dropped the pan to install a deeper pan & found gunk on the magnet about twice the size of the magnet. There was also a few brass specs in the pan. The fluid seemed fine but I don't think it was ever changed.
The truck shifts OK alittle cluck going into reverse.
Any cause for concern?
Sorry no Pics

I would not worry about (if you didn't find any big chunks of steel or band material), since you most likely don't know the history of maintenance. Clean it and put it in the new pan,and do yourself a favor, if the new pan does not have a drain plug,install one before you put it back on. And the clunk is most likely the rear end,which is fairly normal for a Dodge Ram.

Since you will have the pan off, I would consider adjusting the band.

build up of fuzzy gunk is normal.
if you had a lot of gray sludge coating everything inside the pan, and you suspect the fluid hasn't been changed in a long time, you might want to change it again in about 2 weeks. the new fluid will put all that sludge back in suspension and possibly clog up the new filter. that's just my shade tree opinion of why you hear so many stories about how people service a high mileage transmission, and then report that it failed a short time later. the implication is that the service caused the failure, and a clogged up filter would explain why.