Philips Ceramalux 50w coated

This lamp came with the very first Lights of America wall pack light I bought in 1997 for my parents' house. It burned about 3 yrs in that light, and after a break in service, 3 more years in my RAB tallpack in the backyard (dusk-to-dawn & then some). It now burns about half brightness & cycles a few times a night, but still works; I removed it yesterday and noticed the blackening. If anyone wants this lamp for the cost of shipping, let me know, or it will be recylced. Date code: 1K-1 (Oct 1991?)