Postal Savings Of 1943 - Province Of Kwangtung

After extensive research on the web I found that this stamp is a rare postal savings of 1943 in the province of Kwangtung. I also tracked the sale of two copies (one damaged) of this stamp at a specialized auction in Hong Kong (www.zurichasia.com) in a group of 60 different stamps closed at 15,000 HK $. I have confirmed that it is not present in any of the most well-known stamp catalogs.
The only catalog that includes this stamp is "China Stamps Society Specialized Catalog of China to 1949" but I do not have the possibility to consult it. With the information I have I can not give it a value. Can anyone help me in this?

Past link:
https://goscf.com/t/9954&whichpage=1
https://www.stampboards.com/viewtop...f=10&t=33671
https://goscf.com/t/25610&whichpage=2
https://www.ebay.com/itm/China-1943...AOSwUchaJbOa


$10 another type;Forgery?

I do not think it's a forgery. Among the various research carried out I became aware of the existence of two types of overprinting. One with wide spacing and one with narrow spacing. This depends on the small difference in the font size. Probably in the same way there will be a small difference in value.
Anyway thanks.

Here is 3 different font types put together:In the bottom stamp, the
characters are more elongated vertically & the lower left character is different.
from Canada stamper SB