Here is one. Being bit of a novice with engines, I recently pulled apart my type 1 engine to discover the crappy pistons inside.

My engine number says AB 062745.

To me thats a replacement case for a type 1.
My piston size says 85.45 or so i can read through 3mm carbon build up.

I have a head that looks like a twin port or dual port.

Doing some research i have found some odd things like my engine is a type 1 (1300) to a type 1 from 1966 to 1979 (1600)
I am thinking my 1200 engine is a 1600 repalcement fitted at some stage since 1960 which is the year of my bug.

I am hoping its a 1600 engine with all the old bits still on it. As i see buying and acquiring parts would be easier than a 1200 engine. More power the better. I hope its the 1600 as i drove it many years ago and seemed pretty gutsy.

Would do people think?

Take some pictures, easy to clean the carbon off the top of the pistons

Another case of VW literature only catering for US cars.

What you have was the standard aussie 71-73 1300 twin port beetle engine.

As with most of them it's been rebuilt with 1600 jugs and heads as they bolt straight on and they're cheaper and easier to get than 1300 and give a nice power upgrade.