This Pedal is currently available.
Gallien-Kruger 800RB Preamp
I'm very happy to introduce my brand-new DiCosimo Audio 800RB Bass Preamp pedal! This pedal is based on the amazing Gallien-Krueger 800RB bass amp. The amp came out in 1982 and has been used by bassist from bands ranging from Red Hot Chili Peppers, to Guns ‘n’ Roses, Green Day, No Doubt, and many more. This pedal is an accurate recreation of the original 800RB preamp. The only change from the original design is that the DI output is now after the Boost effect rather than before. The pedal uses a standard 9V power supply. The 9V input is internally converted to +/-15V for the full headroom of the original amp.
https://reverb.com/item/47368490-dicosimo-audio-800rb-bass-preamp-pedal