A S40 front boom and steerer clamp might fit, as the gap between the two S1 BB clamps is 45 mm, and the S40 BB boom is 41 mm OD.
You would need new handle bars as the S1 handle bar clamps are for 25 mm dia and the S30/40 is for 32 mm dia.
The OD of the S1 and S30 Bottom Brackets are 42.9 mm, so Clamp IDs are the same.
A bit of filing on the inside edges of the S1 clamps might be required to clear the welding of the BB boom to the bottom bracket.
I would check with Robert Holler to see if this is actually possible.
From the initial photo of the S1 in the large Laundry, the handlebars seem to be a long way behind the steerer clamp!
When I set up my S1 or S30, I start with adjusting the knee clearance to the handlebars first, by releasing the clamp between the Outer tube (S1 BB) and Inner tube (S1 Handle Boom), and adjusting so there is minimum clearance between the handlebar and the thigh in the upper position.
I then release the Clamp at the steerer tube top to the handlebar Boom, to adjust for the correct leg length, starting with the leg straight, and the heel just touching the extended pedal, then small 5 mm adjustments from there, ONLY using the Steerer tube clamp for adjustments.
I then rotate the handle bar, so parallel to the body, so the wrists are not bent, and check for arm length, so for me, the elbows are at 90 degrees.
I have long arms, so I had to go for a handlebar with a long Drop, WTB Dirt Drops (127 mm drop) on the S1, but was able to get away with a short drop (116 mm drop) Salsa Cowchipper 2 on the S30, due to the 28 degree seat back angle.
If the handle bars are too far away with a short drop handlebar, then the steerer tube clamp needs to be released, and adjusted to the desired arm length, then the Inner to Outer clamp adjusted to the correct leg length.
