They have also updated their webshop to now accept payments in Euros.
Source
From the announcement:
Today we release the update of Hind Commander rules: there are new variants of MDD-500 Defender /MH-6/AH-6 and CH-53E Super Stallion.
You can get them from the Assault Publishing free downloads section.
Please note that also today Assault Publishing online store was updated and now it accept payments in EUR instead of PLN. More details on Assault Publishing page.