Magnapan Model MG 1 compare to model ...MG 1 " IMPROVED"


I just purchased a pair of vintage Magnapan speakers
On the box and on the speakers it says MG 1 " IMPROVED"
 Trying to research:
, What is the difference between MG 1 and MG 1 IMPROVED?
I contacted Magnapan customer service advisors but they said they have not been with  the company
long enough to know  the answer
ALSO....
The speakers work great and I was wondering because they have no rattle or buzz,... that they were probably restored at one time.
what do you think ?
Thank you
rocky1313
I have very fond memories of when I owned the Maggie MG1 improved back in the day. I replaced them with Acoustat 3's...which while being more expensive, larger and all electrostatic...really were not as great sounding! 
If I remember correctly, and this is from long ago, the improved were called this as they slightly changed the grill material and the stand..plus maybe had a modification to the x-over. In any rate, a super speaker that I suspect I would still enjoy today.
Oh I also want to say that Magnepan is very quiet about the details of changes they make. On the current versions, they will not tell the details of the crossover changes. I suspect your loudspeakers might be in the same boat. Magnepan: "We made some changes" 
"...I contacted Magnapan customer service advisors but they said they have not been with the company long enough to know the answer..."

And no initiative to find out evidently? In my day, I’d run out to the shop, and find the guy that did know the answer. Then I’d ask why I don’t have a list of all the model numbers?