@aaronpk GrandStream HT802 works *great* for pulse dialing (optional mode). Have multiple rotary phones in operation using it. https://www.grandstream.com/products/gateways-and-atas/analog-telephone-adaptors/product/ht802
I have thought about using a sidecar (wired) or handheld DTMF (acoustical) generator - they used to have such things. havn't done so yet