Period correct car alarm for Mk1 MR2

[Heaveho]

I'm trying to find something that would have been fitted as an aftermarket accessory alarm at the time my MR2 was new, circa 1988. Typically, the only ones that seem to be still available are the ones that were unreliable, even then. Ideally I'd have a Scorpion or Laserline and have it operating the central locking, but I'm struggling to find anything like that. Any ideas where to look?

[Heaveho]

Dr Doofenshmirtz said:

You want an old MOSS or Sparkrite system
Probably best to set up an alert on eBay for any new listings matching those words, or keep an eye on FB Marketplace.

Yeah, those are exactly the two I don't want!

[Heaveho]

It's more to get remote central locking rather than an alarm. I don't want something modern on it though.