MM,
What more do you want to you? - The markings you are showing are consistent with civilian FNH markings, less the proofmarks wich are supposed to be on the lower left side of the receiver, just under the woodline, and were removed by HVA (on some exemples, you can see a blemished remain of "Fabrique Nationale D'Armes de Guerre" on the left side of the receivers used by HVA, because they used to scrub them). In the early days, HVA usually emitted their rifles the same year / year after the receivers were manufactured by FNH.
Actually, the users of FN Supreme Mauser are too numerous for me to enumerate all of them here, but beyond others; of course, FNH, Weatherby, Sako, Browning all used them.
FNH continued to manufacture the older style until about '63, and other derivative of the Supreme actions (Long, Short, MAgnum and Target) 'til about '75.
The small ring 1640 is very similar to the Supreme, but three years older, the latter being a large ring of course, but the 1640 uses a different bolt head, quite the same as the M/94/96/38, with the ejector cut under the lugs, unlike used on the other Mauser designs. The bolt shroud is the same as the M/98, so is the position of the third lug on the bolt. The action screws have the same pattern as the M/98 and the breaching system is the same as the one used on the M/94/96/38, means the barrel does not bottom on a lip (or flange) into the receiver, but only outside - the M/98 barrel bottoms both into the receiver and on the outside of the receiver.