If someone's made a serious offer on your car, they've answered your question. What you choose to do with the info. is up to you. You're emotionally attached, thats cool . You're asking us what its value is? I for one wouldn't buy it. A car without its original engine has no collector value for me. You can go on and on about the improvements you've made and I'm sure you've made a great car for yourself but to try and sell it to someone else might be a different story. Any deviation from original spec. narrows the market down , that's a fact. Used to be that any Healey thrown on the market got gobbled up quicly. The feeding frenzy is over. When that happens , you had better like what you have sitting in your garage. Thats all the sage advice I have for the day , now I have to go feed the chickens as mornin is just starting to break...Kevin