Only issue I see, Lee, is personally I wouldn't use a traditional SPU on a belt-drive turntable, unless it was of the high-mass variety, with a powerful motor (a la Platine Verdier, etc), simply because of possibly straining the motor system with 30 grams worth of headshell and cartridge, tracking records at 4g VTF.
On a belt-drive turntable, powered by a low-torque motor, it could result in stylus drag (as the combined weight of the above will be significant), and thus potentially increase wow, which will degrade sound quality... Does your Spacedeck have a reasonably powerful motor, in order to compensate for that effect?
That's why I'd usually only use traditional SPUs (those inside fixed headshells) on D/D or idler turntables, and a 'Royal N' on others. See here:
https://www.ortofon.com/spu-royal-n-p-461
That will give you the SPU sound, fitted to a standard detachable headshell on your Jelco, but without the extra mass of the fixed headshell variety of SPU. Just something for you to consider, as in your circumstances it might be the best option
Marco.