We've been over this several times, and I'm yet again going to have to point out, with reference to the actual wording of the legislation, that the VCRA (as opposed to the Firearms Act) does indeed say "looks like an actual gun", or words to that specific effect.
It uses the word "actual" twice, ackchyually:
"a firearm of an actual make or model of modern firearm (whether existing or discontinued)" and
"something falling within a description which could be used for identifying, by reference to their appearance, the firearms falling within a category of actual modern firearms which, even though they include firearms of different makes or models (whether existing or discontinued) or both, all have the same or a similar appearance."
https://www.legislation.gov.uk/ukpga/2006/38/section/38
So, yes, this was a real modern firearm that existed for 5 minutes, and even though it's been discontinued,
technically speaking if you made something that looked like it, then it would be a VCRA realistic imitation firearm.
The real challenge would be persuading anyone to prosecute you for selling, importing, manufacturing, or modifying-into one. I'm not aware of anyone actually being prosecuted or convicted under VCRA 2006 S36, ever, but as always I would welcome seeing some case law.