Here are 3rd party sources for Epson parts, including the print head used in the Melco G3 (Epson Stylus Pro 3880):
https://compassmicro.com/products/inkjet/stylus-pro-3880.html
https://www.garmentprinterink.com/collections/melco-printer-parts (Anajet Bulk Refill Ink System is Not Compatible with Melco G2/G3 Printers)
Disclaimer: Melco makes no guarantee of the parts sold through 3rd party resellers.