Really any dealer will have the replacement terminals as they are commonly used. You can also get the terminal block w/ a short pig tail if you feel you need it. While you are servicing at the ignition switch, check the other switches and fuse holder- especially switches w/ power such as the PTO switch if yours has one.

Be sure you have drawn a "map" of the individual wire positions in the switch connector.

If unable to find the terminals at a dealer, your best bet on finding the CORRECT metal spade terminal will be at a comprehensive automobile electric shop.
These shops specialize in automotive electrical systems and the good shops are often the "go to guys" for other car shops.
Take a good "example terminal" with you.

Mcmaster Carr has a great online catalogue on-line. I usually start there for most items. They stock 99.9% of everything listed so delivery is very quick and accurate. Get some dielectric grease to protect what you put back together. Www.mcmaster.com. Link below

Here is a link that might be useful: Link to mcmaster carr

OP - one other thing... if you are using a garden hose or a power washer to wash/clean your tractor, there's a good chance that's where the corrosion started from. L&G powered eqpt is not designed/built to withstand being drenched - particularly the electrical systems - best bet is compressed air or leaf blower for routine cleaning and lite sponge bath for exterior clean/shine.
Typical female connectors will have a metal"tab" formed on the back that is meant to lock into the connector body when pushed in from the rear of the connector. To release one requires a thin, strong metal blade that can slide in from the front and depress that tab enough to allow the connector to be pulled out from the rear. But, follow Mownie's cautions about keeping track of what went where - very easy to get things mixed up.

OP - one other thing... if you are using a garden hose or a power washer to wash/clean your tractor, there's a good chance that's where the corrosion started from. L&G powered eqpt is not designed/built to withstand being drenched - particularly the electrical systems - best bet is compressed air or leaf blower for routine cleaning and lite sponge bath for exterior clean/shine.
Typical female connectors will have a metal"tab" formed on the back that is meant to lock into the connector body when pushed in from the rear of the connector. To release one requires a thin, strong metal blade that can slide in from the front and depress that tab enough to allow the connector to be pulled out from the rear. But, follow Mownie's cautions about keeping track of what went where - very easy to get things mixed up.

I found some of these latching connectors today at an auto parts store that primarily serves garages but also sells retail. They were rated for 14ga. but I can make them work. I found some others that fit the male spade and had a latch on them but were too thick to fit in the plug. These were labeled GM so beware if you are looking for ones that fit in a lawn tractor plug. I may only change the bad one if I can get enough slack in the other wires. If not, I plan on carefully labeling as suggested. Thanks