Help Grading 1870 Japan 1 Yen

I collect all the Meiji issues and these do not look authentic to me as they stand.

Firstly, the strikes are very "weak" and the wear really doesn't look realistic. This can happen if the coin has suffered environmental damage however we don't see other characteristics of that in these cases.

Secondly, the missing beads at the 12 o'clock position on both coins are very strange and not in any of the variants I know. I have around 20 examples of the 1870 1 yen myself and whilst that doesn't cover all the variants I am fairly confident I have seen most if not all of them.
Thirdly, the size of the beads appears to change in the ring as well as the spacing. This is a big flag to my mind.
Fourthly, both of these appear to be a type 2 which is quite a bit rarer than a type 1 ( you can tell because the bottom left stroke of the yen character is as long as the bottom right - in type 1 it would be more like a dot). Whilst it is certainly possible to encounter two type 2s in succession it is fairly unlikely so a small yellow flag rather than anything else.

Finally, I would like to know how different the weight is from the 26.96 official weight.
I have never seen a coin I considered authentic (and I do have almost all my coins graded by NGC or PCGS generally) that weighed less than 26.4g, and those weighing that sort of number generally had a huge amount of wear to them. A coin looking like yours should weigh at least 26.6 grams realistically.

So to my mind these are medium quality fakes. It is possible that they are still silver (if the weight checks out and they are not say 1.5 times as thick as the regular coin) but I would imagine real silver fakes would be made a little better (as the aim would be to pass off regular silver as a coin with significant numismatic value).
I could, of course, be wrong, but I can tell you the likelyhood of that if you let me know more details as to where you got them from as there is a Bayesian probability adjustment that can be made based on context - if for example your great grandfather brought them from Japan before WWII that does change the possibilities a bit.