Readily available Mil-L-7808 near equivalents???

[UCengno1]

We have an epicyclic, splash lube gearbox application in a remote area of Mexico that requires periodic servicing. We qualified the unit using a MIL-L-7808 lube as it usually is available on the sites that use this device. Are there more readily available equivalents or near equivalents (auto trans fluid ?) that could be specified for use in lieu of the synthetic?

Thanks for any help.