Strange Chinese Gas Mask Possibly Model 64?

Strange Chinese Gas Mask found on eBay, no information on the actual mask was provided but it could possible be a M1964/Type 64 which seems to be a Chinese copy/clone of a Soviet MM1 tank crewman's respirator.
There seems to be two variants of this mask, one with the combined exhale valve and voice diaphragm and the other like this variant with the voice diaphragm at the front and the exhale valve under it, similar to a Finnish M61 V3.
The mask seems to take NATO 40mm filters or is at least normalised via a filter intake pipe on the chin of the mask, it has a 5 point head harness system and two Tissot tubes.
Overall for the £14 these cost on eBay they are surprisingly decent.
No idea if this a new production model of the original mask from the 1960s or if it is very well preserved unused stock. No date stamp is visible on the mask.