Excellent posts Matti! Thankyou.
I would be grateful if you or anyone can comment here on my simple observations about the production numbering of the DB600 series engines.
It seems that engines were allocated to manufacture in batch numbers. Until some point around mid-1943, all DB601/605 seem to be 5 figure numbers. Also, these seem to have quite a spread at similar times so, in the summer of 1940, you can see Bf109E with engine numbers like 10xxx upto 60xxx. You can follow this pattern with increasing engine numbering but, with wide variation of the actual number blocks. I suggest this represents number block allocation in the first two numbers, so that at the same time a certain plant might be building the DB605A block 76xxx and, another plant building block 25xxx. This pattern continues through until the series gets up to the 90xxx numbers around mid 1943. There seems to then be some six-number engines but, more definitively, then come the eight-number engines that seem to maybe have a constructor code before the batch/serial number eg. the 001xxxxx or 007xxxxx type of numbers. These engines look to be the mid 1943 onwards DB605A and AS series.
It looks like the DB605D production has 9-number serials, almost all in the "batch" 01110xxxx, with the highest last4 numbered 011102699. There are some anomalies in these 109K-4 listings, with 1170xxxx 8-number listings that probably have left off the first 0, but that looks to me like another 605D "batch"/manufacturer.
Obviously, there are contradictions but, these general patterns are there, I think!? Cheers
SM