There’s always the Lowe Custom Guitars Medium Scale Conversion Neck option. Just bolt one onto any long scale bass body with a standard Fender neck pocket and you’ve got yourself a 32” scale bass. I’ve owned a couple and they are really well made necks.
Here’s the description from the Lowe website:
AVAILABLE | LOWE CUSTOM GUITARS
32″ MEDIUM SCALE CONVERSION NECK FOR BASS GUITAR
The Lowe Custom Guitars 32″ medium scale conversion neck for bass guitar is CNC-milled and finished in the USA and includes a logo and serial number.
The medium scale conversion neck concept is surprisingly simple. Our unique design moves the headstock and nut to the location of the first fret on a comparable 34” long scale neck. It also adds an overhang with an extra fret at the bridge end of the fretboard.
This innovative configuration yields a 32″ scale, 20-fret neck that will convert a standard long scale bass to medium scale without any additional modification. Imagine de-tuning a bass one-half step and putting a capo on the first fret and you’ve got the idea.
The Lowe conversion neck is a direct replacement for an American-spec 34” scale neck, and the process is 100% reversible. The neck fits any P-type or J-type bass body from manufacturers like Allparts, Guitar Mill, Musikraft, Rosser, Mighty Mite, USA Custom Guitars, Warmoth, WD Music, etc.
Features:
• CNC-milled and finished in the USA
• Roasted maple neck with roasted maple or rosewood fretboard
• Mother of pearl dots
• Satin urethane finish
• Flat black or embossed shiny chrome Lowe Custom Guitars logo
• Scary Creative silver ink dry transfer serial number
• Shiny chrome bullet headstock truss rod adjustment
• Carbon fiber reinforcement rods
• Installed Tusq nut
• Installed Hipshot Ultralite shiny chrome machines
• Installed Hipshot or Gotoh shiny chrome string tree
• Installed carbon steel inserts for 8-32 machine screws