I agree with everything stated by @cleeds
I have 2 spares for my Betas. One of them needs service and some cosmetic help (bought it sight unseen as a second spare).
In the spirit of helping a fellow Beta owner, I would be willing to sell it to you. I would recommend that it goes straight to Bob S at PSAudio for checkup and service.
Bob serviced one of mine and found it needed a pot replaced and a small caps, It works great.
I suggest you diagnose the speakers before you decide how to proceed. Inspect all drivers, clean and measure the LPads and factor in 500-750 to replace (at least) the SOLEN caps which are known to fall out of spec. I replaced mine with new SOLEN to maintain originality.
Check if they still have the proper servo control woofers (2nd from top on each tower - should have a second set of connections with either a resistor or a small pc board). Visually inspect the LEMIMs (large rectangular drivers). Those are very hard to come by. Replacement diaphragms are being completed for the LEMIM and all others are currently available.
After checking those and coming up with a budget, then let me know if interested on that spare SCU. There is one on ebay right now (not mine).