Um, 78s aren't vinyl. They're shellac.

Even WITH modem to modem connections like you're describing, you're looking at a minimum 120ms latency. I worked for an ISP for years. First hop from modem to terminal server is 120 ms minimum on a dialup connection, period. First hop meaning NO INTERNET INVOLVED.

Finally, 56k modes can send 53kbps easily. I dunno who in the world is informing you, but I really suggest you seal up your ass and stop talking from it.