need replacement amp for M&K Volkswoofer

I have a M&K Volkswoofer I bought in 1978. It was one of the first powered subwoofers on the market.The driver is in good shape, but the amp is blown. I would like to keep it vintage and have been looking on e-BAY, but nothing has shown up.

The driver has two 4 ohm coils. It is in good shape, I had the foam surround replace 15 years ago. Sounds good if you power it directly. I also measured voltage on the power supply output wires. The amp is some kind of oversized IC maybe, providing output seperatly to each of the voice coils. As I rememeber it, the amp output was about 70 watts.

The one thing I have seen is MCM Audio Select 100 Watt Subwoofer Amplifier Module | 50-6272 (506272) | MCM Audio Select It is a 100 watt plate amp. It has a single output. I assume that I can wire the two voice coils in series and connect it to the single output. + to - to + to -.

Can anyone suggest other replacements?
Some of those hybrid amp modules will still be available. What's the number on the chips? Does it start with STK?

Maybe a couple of LM3886 chipamps could reuse the original power supply and heatsinks. Or a higher power chipamp like the Sanyo STK404 family.

In a pinch, you could just run it from a random stereo receiver or integrated amp from the thrift store. Or pick up a used (semi)pro amp; something that does 100w/4ohms should be cheap.
Bought the SI-1050G on e-bay for $30. Actually 2, just in case.

The seller said that the G could sub for the GL, but not vise versa.

I will let you know how it sounds.

Thanks again, in the back of my mind, I thought I should be looking for the chip but assumed that the amp was too old and wouldn't be able to find it.