Try drilling a hole and inserting a hardwood dowel. The best holing power
would be to drill a hole through the edge of the bench and insert a dowel so
that the threads enter the grain at right angles instead of through the end
grain.
I would probably buy the brass inserts and thread them in and use machine
bolts.
I don't think you would get good results with filler.
max

I have a solid redwood bench that I made over 30 years ago which I'm
rebuilding. I originally secured it with steel screws which, over
time, corroded and destroyed the wood that surrounded them. She
cleaned up well, and I know I'll be able to put it back in service,
but have to decide the best way to do so. My first idea was to fill
the holes with a sythetic wood, drill it out again and replace old
hardware with SS screws. Dowels are another alternative, but more
difficult given the tools available to me.

Anyone care to offer some suggestions of the type of filler material
to use? Any other tips that might be useful in the project? Your
help and advise would be appreciated. Thanks!

T Will