The standard Beetle rigid brake pipe lengths are well documented but of course the Puma pipe from the front to the back is shorter, and my disk brake conversion also changes things.
A Beetle has a wheelbase of 2400mm while the Puma is 2160mm, 240mm shorter. I therefore had a 1950mm pipe made up to go from the front to the rear. The four short pipes at the back are the same, but since a too-short pipe can’t be stretched I had them made up at 200mm, 360mm (x2) and 660mm.
At the front I measured and found that I need 760 and 1110mm from the Golf master cylinder to the flexible hoses. The 760mm was spot on but the 1110mm turned out about 250mm too long. Dunno how that happened.
The next question is how to plumb the dual master cylinder to the wheels. Dual diagonal looks fail-safe, but I’m pretty sure it won’t work with a mix of disk and drum brakes. Also, I don’t want to change the single pipe to the rear for two pipes. So I will just connect the primary (closest to the pedal) to the front brakes, and the secondary to (1) the rear brakes (one hole) and (2) the brake light switch (other hole). I might need a proportioning valve and / or a residual valve though.
I ended up using a Golf brake fluid reservoir, I think the correct part number is 1J1 611 301. $25 off of eBay, and that for a second-hand part. Eish. Well at least it included the cap / switch (1J1 611 349). I should be able to top the brakefluid up by removing the right front wheel.
The brake light switch is 113 945 515H a.k.a. Schalter 101 973 885.