Thanks for explaining the philatelic connection; I know the type of overprints you refer to; others used perforated initials. I regret not collecting more of these types way back in my philatelic period, but I got diverted into postmarks which rather left behind the actual stamps...
Thanks also for clarifying that you are not UK-based. I now appreciate better the constraints on your research of UK companies. Hopefully the following isn't teaching you how to suck eggs, but a good starting point (which strangely did not work in this instance) is to check the National Archives online catalogue for registration year and to obtain a broad range during which the company was dissolved, and then to search the London Gazette online archives for more detail, especially concerning the circumstances of winding up and the date of striking off. Armed with a TNA company number, a xerox of the company file can be ordered (if it survives). Newspaper searches usually fill in a lot of the gaps.