I thought I posted a reply but must have hit “cancel” in haste. If it appears somehow forgive the repeat.
I wear a men’s small size glove. I’ve played many of the great flutes out there. My “small hands” had no problem with an Olwell pratten. (known for its good sized holes and volume among other great things).
I am often told by people they can’t play the simple system flute since they have small hands. When we test that hypothesis palm to palm they often find their hands are larger than mine. Since you and I are not in the same room we can’t test that one out. But…
It is often the stretch and the finger placement. If you are switching from a Boehm flute the first thing you will need to adjust to is using other parts of your fingers to close the holes. Many players use the finger tips on first two fingers on the left hand, while the rest are placed in various positions to close the holes and allow for ornamentation. This varies from player to player. I know some players who don’t use their finger tips at all.
As for your embouchure. That will adapt to the flute you are playing as you and the instrument search for the sound you are desiring. But you won’t lose it for your Boehm flute playing. Your brain will know which instrument you are playing and your body will adapt.
Keys on keyed flutes are seldom operated by the finger tips in the same way you would on a Boehm. So thinking your hands are too small since you can’t reach those holes or keys the same way you do on your silver flute is selling your fingers short so to speak. I open the cnat key with the side of the first finger on my right hand betweeh the first two knuckles for example. It would be impossible to open that key with your fingertips.
If you know players talk to them. Ask them if you can handle their flutes. If you don’t have any in person people to discuss this with talk to us here. Check out some of the free videos on the Online Academy of Irish music. See how the teachers are holding their flutes. I think they still give you a week for free. YouTube videos of famous players sometimes give you glimpses of the hands, though camera operators often think we want to see the faces.
Good 6 keyed flutes from good makers sometimes come up used, but often at a premium since the buyer is skipping the wait time if a maker is in demand. And many fine flutes are available with shorter waits because no one famous has happened to record with their instrument.
Buying an antique can be a minefield. There are some great restorers out there who have done up and instrument and can stand by their repairs, but an unrestored instrument can cost far more than its purchase price in repairs, not to mention it may not have been created to play A=440 or in the key of D. So unless you know who you are buying and what to look for its hard.
Modern 8 keyed flutes are rare because most of the modern makers are building with the Irish flute market in mind. And Irish flute players have decided low D is low enough. A good 8 keyed flute is wonderful. But making that mechanism is expensive and requires expertise. Many makers just don’t want to make them.
An excellent conical bore wooden flute with our without keys is going to be pricey. We are a niche market, and there is a lot of detailed labor and experience that goes into making one of these beasts.
If you see something at the Irish flute store you do have the advantage of their giving you a trial period.