Details on 1930s dadao sword

All of the dadao with big chunky brass guards with markings like these have been modern fakes. Chunky brass guards like this are rare on historical examples, and the few supposed-to-be-old ones I've seen were unmarked.

The guards combined with the very round and even rings is pretty conclusive for me: fake. You might find something interesting if you unwrap the handles (and maybe remove the grip scales) and look at where ring and tang meet.

Fakes like these are also usually pretty heavy, with the blades being quite thick near the tip. I can't see the spine very clearly, but these like like that.

Finally, two such similar swords would be quite unusual.

Why is this? All of the photos from this period show soldiers with swords that look exactly like this.

If you can link to a photo that shows a soldier with a sword exactly like this, I'm interested in seeing it. There are many with S-guards and round and rectangular plate guards, and there are many with these "ram's horn" curly-tip guards. The older curly-tip guards are forged iron, usually made of two pieces sandwiched together. This jian shows the classic forged construction:
mandarinmansion.com/item/seven-stars-militia-jian
Later examples often have brass guards, but these are usually less wide (top to bottom) than the ones on your swords, and are almost never marked. Some examples:
www.antiquechinesesword.com/dadao
mandarinmansion.com/item/1930s-republican-dadao
mandarinmansion.com/item/tongzhou-incident-29th-army-dadao

The pommel rings are usually forged from the end of the tang, and are usually rectangular in cross-section rather than round. An example where a typical pommel ring is uncovered:
www.swordsantiqueweapons.com/s080_full.html



How much thinner? They're commonly about 1/2 the thickness at the widest point, compared to the base. Some have more taper, others have less (the ones with less taper are usually thinner at the base).

How thick are your blades at the base and the widest point? How heavy are the swords?



Since the round pommel ring is a separate piece, you'll be able to see how it's attached.



I've seen and handled real ones. I've seen many photos of real ones. I own some.

This is a very common style of fake:
www.aliexpress.com/item/32357851389.html
and has the same guard and pommel ring as your two. I have never seen a non-fake with a chunky brass guard marked like this, nor one with a smooth round pommel ring. These are common features on fakes, so IMO they good signs of fakeness.