Took apart a DWDM XFP optic left over from the 140km TOSLINK stuff, A lovely person sent a load over that they no longer needed and they were part of my back up plan if more optics didn't work

Anyway it seems like they would not have worked anyway because the chip is a
GN2010EA that has CDR (my enemy)

The Receiver/Transmitter Optical Sub Assembly (ROSA/TOSA) may be useful for future fun though, Especially since the TOSA seems to have the DWDM Channel written on it, implying that it's statically tuned for that wavelength...