Help from experienced sewers and knitters please

On the pants, if you get a cotton in the dark color, you could dip it in a bleach solution, rinse, dip a bit less length, rinse, etc to get the gradiated color change. Then wash to get any residual bleach out so it doesn't change more.
There are some light weight denims, maybe look at second hand clothes at the thrift store for inexpensive options. Or is it a corduroy? 21wale corduroy is fine & light weight for a good doll proportion.
You may also find the sewing projects thread useful. I'll go pull up that link.

 

You may be able to achieve a similar look for the trousers by

• finding an existing pair of wide leg pants/trousers in black. Alice's Collection might have them.
  
• dipping the legs in partially in bleach to make the lower part lighter
• washing the bleach out and then dyeing the lighter part the desired color.

 

Here ya go:
/threads/what-are-you-currently-sewing-for-your-bjd-vol-14.833712/

Great place to compare notes with other sewing people if you have construction questions or want to share your sewing as it proceeds

There's something similar for knitting as well.

Another thought on the knit remnants on his sweatshirt, maybe scavenge a knit top from the thrift store, and cut pieces to use?

 

Glad to help : ) Good luck with your project!

 

That top is definitely two knitted tops, with the distressed bit layered on over the intact (lighter) top. I should think getting or making two identical doll long-sleeved t-shirts in white and beige, distressing the beige, and layer it over the white, tacking it in place at appropriate spots to keep it neat, would definitely work.

 

If it was me, I'd do it in this order:
1. Bleach test scraps of the fabric so that I know what to expect. If it isn't working for any reason, I'd want to know before putting in any more work.
2. Make the pants.
3. Soak the pants in water for half an hour to saturate the fibers, then wring out the excess water. This will help with getting the soft gradient of the bleached area. If bleached dry, the fabric will work as a wick and pull the bleach up, creating a more distinct edge.
4. Dip the pants in bleach. What concentration and duration should be known from the bleach tests in step 1. I'm guessing that a deeper dip first and the shallower and shallower is the best way to create a soft gradient, but again, the tests should have already shown the best procedure.
5. Rince thoroughly and let dry.

 

The long-sleeved white layer of the top looks like a thermal knit, definitely not stocking stitch. I don't know how to reproduce that in handknitting, but you might do some searching for "thermal knit handknit" and see whether you can find a pattern somewhere. The rags of the tan distressed layer look like a broken rib of some kind--maybe 1 knit stitch alternating with 1 stitch in garter? For both parts, it looks like you would need a very fine gauge to make the stitches look proportional to the doll.

Not sure how helpful these random thoughts are, but that's what strikes me as I look at the picture.