You can see it has 16 pins with 6 inverters. There is a power Vdd pin 1 and ground Vss pin 8. And two unconnected pins 13, and 16.
The 4069 is essentially the same chip. Here is the 4069 data sheet. Here is a picture of the chip:
The 4069 is a 14 pin chip with 6 inverters. Pin 14 is power and pin 7 is ground. There are no unused pins.
The two chips should be the same and interchangeable. Of course we of discerning audio tastes can sometimes hear subtle differences in devices. So of course we have to build both and see what they sound like!
RunOffGroove.com has notes on building an adaptor. You can check out the instructions here.
I had the PCB designed for the 4049 already and PCB manufacture these days is pretty inexpensive. I updated my 4049 design and had some boards made. It cost about $25 for 10 boards. I figure that’s worth the couple hours time it might have taken to make the boards myself, and I get high quality boards! Manufactured boards have two sides, are pre tinned, and have tighter tolerances which allow you to get more in a smaller space. I used PCBWay.com low cost prototyping service to create these.