PSA: Since the OP's links are broken, I added a note to it with a link to a reply with a still-working link.

Recently I found that someone has made a SoundFont of the ESFM synthesizer and it sounds quite similar although not exactly the same.

Has anyone tried this ESFM SoundFont? https://dropbox.com/s/s7muqffctbty4ju/ESFM.SF2?dl=1

It's a 703 MB file though made by some Japanese guy, I use it in Virtual MIDI Synth and then load the SF2 file in it. Give it a try, the MIDI sounds really nostalgic with it, quite similar to the original hardware ESFM.