I’m not sure that the SPA2002 supports pulse dialing. One that does, for about the same price is the HT802; see
You can set it up so the two phones can dial each other. Once configured, no internet connection is needed.
However, it’s a lot more fun if they are set up as working phone lines (requires connection to a spare Ethernet port on your router). IMO, a good service for a hobby project is
because monthly cost (per line) is only $0.20 ($0.95 with E911 service). You pay $0.0082/min. for domestic outgoing calls and $0.0043/min. for incoming. You get a small credit at signup, so you can test the whole system without making a payment (other than buying the HT802).
A PBX is probably overkill for your project, but if you want to set up a system with three or more phones, we can help with that.