Surly makes 130 chainrings in 42 and many other tooth counts,
great as a single or an inner chaintring on a double, theyre Stainless steel.
Long wearing..

Salsa another QBP brand name, has Replacement rings Aluminum 7075.
Sugino makes spare chainrings on the cheap end,
TA on the jewelry level of the spectrum, also a 7075 alloy..