Alternator confusion

[Ronin]

Hello

So my alternator went bad so I ordered a replacement regulator I found a nasty suprise inside the casing

Someone has ( I think) snapped off the bolt that holds the regulator and drilled another one slightly off OR bought the wrong regulator so drilled a hole to fit it.

It's an HC-Cargo 138310 regulator which apparently corresponds to vag part numbers: 046903015F, 059903015 and 078903016.

The Hella regulator I purchased corresponds to part number 028 903 803D from this thread: http://forum.a8parts.co.uk/showthread.php?t=16044.

So the question is: Is the original regulator found wrong one and the one I purchased is correct? and having that damaged/wrong thread hole it probably writes the whole alternator off. Since I have 2 new bearings and a regulator I'm probably best off buying a used 2.8 QS alternator from forum sponsors and putting those new parts on it?