Thank you for the thoughtful responses!
As an interim, I will try to make the rod length adjustment. Long term goal is to upgrade the entire pedal assembly (if possible/practical) to something like what Vintage/Seduction/Fibersteel uses if I can make them fit without major surgery. Has anyone attempted this?
Yes, I have attempted it. And yes, it is necessarily major surgery. I detail the process here. (Pedal stuff starts about a third of the way down).
Fifty or so hours into it, here's what I ended up with (Left top is 550-0060; right side is my homemade junk):
Easiest way to do this probably is to spring for the Fibersteel pedal kit. I believe it comes attached to a plate and you could just template that over the bulkhead on your car, drill the holes and weld (or even bolt) the whole thing over top of it. You could saw the stock VW tunnel simulator bit out or maybe even leave it at least partly intact. It's probably helpful to keep the bulkhead from flexing, as I recently discovered.
Getting this done, by the way, will almost certainly require that a section of floor be cut out. I tapped the steel framework in mine for 1/4x20 threads and will return the floor to service with something like two dozen stainless buttonhead screws.
With correct-looking pedals you'll be the envy of all your Spyder friends. You'll walk a little taller, speak to girls more confidently, stand by with a quiet proudness whenever anyone leans into your tub to check out the goods.
What you won't gain is much leg room.
From what I have read, the standard VW type dual circuit master cylinders require 8 inches of pedal travel in order to operate the brakes in the event of a circuit failure. That's 8 inches at the pedal face.
That's what I get with mine where it is. I'm 5'7" and sit comfy with the seat adjusted three notches forward. A while back I put my 6'1" neighbor in the driver's seat and he fit, but didn't love the driving position. The car's only so long, the cockpit is only so deep. The original cars were even shorter and they got away with the stunted pedal rig they used because they didn't have and probably had never heard of dual circuit brake systems. Carey Hines tried to put one in a properly-dimensioned replica in recent times—and couldn't do it.
All that said, I lend my voice to the chorus of those telling you to upgrade asap from the line lock system currently serving as your parking brake. This was not one of McBurnie's better ideas.
It is likely that you'll find your rear brakes are discs (which is good) but are not provisioned for a cable pull (very bad! Off-road use only!) If this is the case you'll have to replace them with either expensive disc calipers that have the requisite fittings for a proper e-brake, or with stock old-school VW rear drums (which actually work just fine, it is reported).
You might get lucky: my car came with the proper disc brakes provisioned for the cables.
From there you can either source a bug handle, as was the replica standard until recently, or spring for the Vintage Speed replica 550 parking brake.
Welcome to the madness, by the way.