Unusual King Size K-1?

[KvK-1]

Hello! Posting here hoping for some information. My dad passed away recently and we've found a big box full of Matchbox.

The one I'm stumped by is an unusual looking King Size K-1 - https://i.imgur.com/YvJjqMd.jpg - unlike every other example I've seen online, the jib is red and a different shape.
I was wondering if it's a sample-for-approval or some kind of corporate freebie edition, as my dad worked for O&K in the 70s/80s.

Thanks in advance if anyone can shed some light!

[Idris]

Here's the important part of that image:

[yellowfoden]

Welcome to the forum KvK-1.

Having studied in detail the evolution of the Lesney Kingsize K1 O&K Excavator from pre-pro through to superking I can’t say I have seen an arm and bucket arrangement like the one you have shown on a Lesney
It looks very much like my NZG model from W. Germany as they use a red hydraulic sleeve on theirs. The grey bucket and grey hydraulic is interesting.
Here is a side by side pic of yours and an early Lesney and you can see they are similar in body work but not the same.
The hubs and tyres are also very interesting. Are the tyres soft rubber please?
Your model could well be an RW Model or Ziss but this is usually cast on the bottom. Any chance of some more photos taken from the other side and out of the box please?

It may be that your Dad placed the RW model into the K1 box to preserve it, or it could be how he was presented with it, are there any other loose O&K models in the carton?

Bert