Syncro twins?

1
All,
Just a query, perhaps novel.

Two relatively similar syncros I know that have VIN numbers exactly the same except for the last number, one ends with a 2 and the other is 8. So on the build assembly line, a mere difference of 6.
How far apart time-wise might their build completion have been? Qualify as twins? Near enough to be twins? Minutes? 30 minutes? An hour? Best guess? TIA.

Cheers.
Ken 
2
Hi Ken and all,

My Syncro's, Synthia 604 and Sylia 602 are both ex telecom and are definitely sisters separated by one sibling.
The avocado farmer Tony that I bought Sylia off had 600 too.
My neighbor Marty recently bought 600 and dubbed him Merlin.
It's pretty nice to see them all hangin out together.
Does anyone have 601 and 603.
I am attempting to get Synthia back on the road in the next couple of weeks.
Everade do you still have those front disks?

Cheers
Paul
Byron bay