Galba

Well for Roman Egyptian coins, I'm happy to look them up for you :) Hang on while I crack open Emmett...

Emmett 170(2), R1

There are two different obverse legends for Galba in year 2 but from what I see remaining on your coin, yours would be:

Sigma E P O V I Gamma A Lambda B A A V T O K A I Sigma Sigma E B A

The reverse is Bust of Alexandria right, wearing elephant skin headdress; A Lambda E Xi A N Delta P E A

The date, LB, means regnal year two (68-69 AD) and is seen on the obverse under Galba's chin.

Emmett 170(2) is the same as Milne's 326.

Dunno. My only Alexandrian reference book is Emmett's and in the back he has a cross reference. It shows 170(2) as being the same as Milne's 326.

If you find someone with Milne you can ask him/her to see what it shows.

You might also try searching various sites by the Milne number to see what comes up. It's possible that Milne further divides the type based on things Emmett considers minor (ie, there could be more than one Milne number for a given Emmett number).