just wanted to say got a century tantal and no keyhole at all.Put 300 rounds and no issues.Used silver bear 60 grn.TT for begin serial.just my 2 cents

Glad to hear.
What's the information on your triggerguard tag (model #, barrel info, date of mfg)??
I recently purchased a Tantal from Centerfire Systems that fired and functioned flawlessly. Model # RI-1594-x with 1:8 twist, 4-groove barrel built on 8/26/09, serial Y0020xx.
Here's a link to my
Tantal Review with some pics.
thanx nice pics.

11 1990 cs3819 thats what it says on side.wish my computer would let me post pics.
Sorry, wasn't clear about the numbers needed.
The numbers on the side of the trunnion are meaningless when built on a US receiver (except to see if is was built using a matching numbers kit).
If your rifle had a tag on the triggerguard, that will contain the model number, barrel configuration, date of build and serial number of the US receiver. That's the info I'm interested in learning about. A partial serial # is great (i.e. Y1234xx or TTL1234xx, etc.). If you don't have the triggerguard tag, the model # will be on the box.
I'm presuming it might be a model RI-1594-X with the 1:8 barrel, like mine.