Two Yak-9UT questions that I have

[IceFire]

First to start off with.. I really like the Yak series of fighters and I've been building a few single player campaigns for them as time allows. I'll probably be releasing the bunch individually sometime after the 4.10 release. So when I'm online and I have the option I'll usually pick a Yak instead of the La-5 or MiG-3 that everyone seems to fly (depending on the year).

Today I was having a blast in the Yak-9UT and remembering how much fun it was when this plane was added to the game. But I have two questions, one that has bugged me a for a while, and one I just noticed.

1) Whenever I read about the Yak-9UT the armament seems to list various different configurations. Usually they state that the 20mm ShVAK hub mount is changed to either NS-23, N-37, N-45, etc. For the synchronized guns I only ever read that the two 12.7mm UBS were replaced by B-20 cannons. In-game the armament is N-37 and two ShVAK 20mm which doesn't match any of the descriptions I know. Any idea why?

2) In IL-2 compare, the Yak-9UT armament is listed as:
Shvak 120
Shvak 120
Sh37ki 30

I always assumed it was the same cannon on the Yak-9T and 9M and those are both listed as NS-37.

When I tried to look up Sh37 I couldn't find anything.

Anyone able to shed some light on either of these two?