Mills .75 Serial Numbers
Having recently re-discovered the delights of small diesel engines, after an interval of 45+ years, I wanted to acquire (among others !) a Mills .75, being my first love, to see perhaps if, this time around, I could actually get something to fly reliably (with r/c?) under it's power (I use the term loosely). I actually ended up with two examples, both as yet new and un-run. I firstly acquired an original Mills but being an absolutely mint example, still in it's original box, etc, I decided at this stage, that it was too precious to use in a model. So, I kept my eyes open for, and duly acquired, an Irvine replica, which I'm told are very practical for 'everyday' use.
Now to my question: Does anyone here have knowledge of the serial numbering used on these engines? My original Mills is numbered 67700 (67 on one lug and 700 on the other, written as 67700 on the factory inspection certificate and guarantee). The Irvine replica has the serial number 02537. Can anyone tell me whether the date of manufacture can be deduced from either serial number, and is my original engine a series 1 or 2 ? - I believe I am right in thinking there were two series but have no idea of the difference between them - perhaps somebody can enlighten me on this as well. Thanks, Alan