It sounds like you’re looking for vintage silk thread in Mustard 17, specifically in sizes 00 or A, for wrapping bamboo fly rods. Here’s some helpful information:

1. Understanding the Thread Sizes:
– Size 00 (or “A”) is a very fine silk thread traditionally used for delicate wraps on bamboo fly rods.
– Mustard 17 is a classic color often associated with vintage rod restorations.

2. Where to Find Vintage Silk Thread:
– Specialty Fly Fishing Suppliers: Some shops still carry vintage or reproduction silk thread.
– Examples:
– [Golden Witch](https://www.goldenwitch.com/) (offers high-quality silk thread)
– [The Classic Fly Fisherman](https://www.classicflyfisherman.com/)
– [Bellinger](http://www.bellinger.com/)
– eBay & Etsy: Often has vintage spools of YLI, Gudebrod, or Pearsall’s Gossamer silk thread in Mustard 17.
– Rod Building Forums: Check forums like [The Classic Fly Rod Forum](http://classicflyrodforum.com) for collectors selling old stock.

3. Modern Alternatives:

Vintage Silk Thread for Bamboo Fly Rods Sizes 00 OR A - Mustard #17

– Pearsall’s Gossamer Silk (still available in some colors, though Mustard 17 may be rare).
– YLI Silk 100 (a close substitute if vintage isn’t available).
– Belding Corticelli (another vintage brand sometimes found in collections).

4. Tips for Authentic Restoration:
– If using for restoration, ensure the thread is untreated (no nylon or wax coating) for proper adhesion with traditional rod varnish.
– Some modern threads are “size A” equivalent but may not be exact matches in color or texture.

Would you like help locating a specific seller or verifying authenticity of a thread you’ve found? Let me know how I can assist further!