Serial # 14061. Been "told" this was a 1981 based on 5 digit serial number. Not sure if this is because of the first digit or last digit. Not sure what the rest of the numbers mean. I've looked on this site and found serial numbers charts for other later models but not earlier. Just that it is based on 5 to 6 digit serial numbers for the year and month. Since I'm needing a workshop manual, mechanical and electrical, I went to the site, https://www.kubotabooks.com/AutoIndex/index.php?dir=Engines/ and I don't think any of these are the correct ones for the D100A engine for my year. Can't quite tell. If theses are not the ones, can I be directed to find one that is if it exists? Have gone to other sites on the internet and my browser pops up virus threat. Appreciate any help. Thanks.