KXD-807F CN1708.1 is written on the 8 pin chip but that doesn't seem to lead me anywhere.

 

Probably an "in house" custom marking. It is unlikely you'd ever be able to find the answer to your question.

 

I don't know what that one is. If you want to make something with a similar part, we can find many examples.

 

If the positive power supply is on pin 1 and Gnd on pin 8, I'd suspect that it's something in the PIC family. But maybe that would be a false trail.

 

Microchip PIC12CE518 would be a possible candidate.

 

If it's a mass-produced product made in China it is likely an ASIC (Application Specific IC) created for that purpose.

 

In other news there is an abundance of libraries for lots of devices that can read out the IR codes and send them back to your PC so you can "roll your own" sending device. Adruinos and ESP-xx are two that come to mind. I've worked with the ESP things and you can get them packaged on a PCB along with a USB-RS232 interface for programming and debug (and getting those codes!)

 

There are some very cheap Chinese microcontrollers.
https://cpldcpu.wordpress.com/2019/08/12/the-terrible-3-cent-mcu/

Google pointed me to:
http://www.szkexinda.com/?products_26/807.html
and (insert your favourite happy profanity here) there's the data sheet:
http://www.szkexinda.com/static/upload/file/20210522/1621648461281855.pdf
I guess it's possible they buy microcontrollers and program them, or they could order them already programmed.

Based on another link to a collection of remote codes, it's remotely possible that the "807F" means "NEC protocol 807f".

 

If it's a mass-produced product made in China it is likely an ASIC (Application Specific IC) created for that purpose.

Is there any datasheet available?