Go with the droppers that will fix the problem with each rail solder to a wire power feed directly.

It will by pass the layer of oxidation between the rails and rail joiners.

If the rail tops are not physical worn they will be serviceable for years.

RH

Thanks RH. That was my plan, but from the sparking (albeit slight) at the points it would be prudent of me to include all thirteen sets of points. I never figured that I would be doing "upside down" soldering at 75 though!

I would be tempted to do a little as possible only adding droppers and feed wires only where they are necessary, especially on a big layout., Perhaps some sort of face mask or visor would be useful when going under?

As for sparking at the points, is this as the wheels run through the switch rail section where the closure rails can be pushed out of position by heavy rolling stock,

Perhaps a general question in the questions section would bring out other peoples experience of dealing with this?

Try here   http://www.rmweb.co.uk/community/index.php?/topic/114509-peco-electrofrog-code-100-small-radius-point-wiring/

and

http://www.rmweb.co.uk/community/index.php?/topic/139855-modifying-old-peco-electrofrog-points/

good luck.

Thanks for that advice RH. It occurs to me that the running problems associated with corrosion at the joiners happens mainly at the remote areas of the layout, so my guess is that when wiring up I found it easy to put in a large number of droppers adjacent to the operating "pit" and made do with fewer elsewhere. However, I now see that I can access the remote areas quite easily from underneath if I remove the upright screen boards that form a double layer to the backdrops (wood/trees). Re points; I need to dig out a spare from the box and have a look at the wiring arrangement - pretty sure they are code 75 insulfrog. Once I've got one in my hand it should become clear what it needs for a permanent fix. Visitors from UK at the moment, so no further progress for a few days.