I took on a project like this a few years back.
Same deal.
No magazine, nor clippy thing to hold it in.
The magic chappeaur noire had the last magazine in history.
Nurmich had the last clippy thing and screw as well.
At the time international orders were suspendith.
I knaw'd awn the bed post for a fair bit until they allowed out of states sales.
When I got the pieces, they showed 0 in stock.
Things may of changed since then.
WGP's, Numrich, Brownells or a WTB in the EE.
Further note, these are a bit of a rare beast.
Only 16,000 and some change were built.
Winchester introduced them in the late 60's to the early 70's.
They came after the 69A's.
Winchester offered a single shot and a tubular magazine in this era.
I wish you well on finding your pieces.