Modifications:
I added two chainrings where there had been only one.

The original configuration had a 34 tooth timing chainring, 46 tooth chaniring and a
chainguard on the outside. All this was assembled on a standard 110mm triple crank set.

I replaced the 46 with a 52 tooth,
and replaced the chainguard with a 34 tooth.

This configuration, tho unusual, is functional for trailer towing
or high speed cruising.
Click to view a larger image of the modified gearing.
I have not chosen to add a front deraileur at this time.
I have to manually move the chain to the gear I intend to use.

I pretty much know what gear I will need and set it at the beginning of a ride.

If towing a trailer, I use the 34,
if looking for speed, I use the 52.

With this configuration, the bike has 42 gears.

I do not intend to  keep this configuration long, as the chain rubs slightly
on the 52 when using the 34, and largest cog combo.
Once I manage to remove the crank arm I will swap the positions of the chainrings.
I hope to have (from bike center towards outside):
34,34, 52
At some point I may change the 52 for a larger chainring,
possibly a 60 for some serious cruising. :)