For the large pushbutton guns they only maintained facilities in two cities in 1977 during the transition.So John, you are saying that at some point High Standard maintained two facilities (East Hartford and Hamden) and that some SH guns were marked with either adress? And are you saying some ML (East Hartford 107's) carried SH serial numbers (with or without the SH marking)? In the last days of Connecticut High Standard is it possible that they were using up previously marked or problem parts from Hamden days and in their haste to close up shop mistakes were made in the markings of serial numbers?
All this serial number markings issues is meaningless to shooters. I think the poster is a shooter not a collector and as long as the gun shoots well and is presentable for fit and finish, I suspect he will find the gun to his liking! The accuracy over the years, regardless of the manufacturing at various locations, has always been stellar. Fit and finish may have varied but in most cases over the years these guns have been an excellent choice for a target gun. Just my opinion and other's opinions may vary.
Slant grip guns were basically discontinued in Hamden but some leftover parts were used to complete small numbers in 1978 after HSI took over ownership. The Military grip guns first assembled in East Hartford used up old Hamden marked barrels and this practice was again repeated in early 1978 when the company ownership changed.
It is most likely that they were not mismarking parts but rather using previously marked parts.
You would be surprised by the number of target shooters who have requested the ship date and configuration of their guns. Some do care.
The accuracy while it has always been setllar there was always some variation, but as the manufacuring methods changed so did the accuracy. I have a memo from Gary Wilhelm about that very issue. When they were selecting a barrel for the fluted barrel 104 series Supermatic Trophy to be sent to the NRA for evaluation , they target tested moer than a few barrels. I have the targets. The NRA review was very favorable especially since they got a very good barrel. If there had been no variability they would not have had to use target tested barrels for the much later MODEL 10-X.
I am certainly not going to treat shooters and collectors differently or try to guess what they really want to know. I provide what information I can and they can do with it what the want.