Here are the new photos I promised...
My Type 3 Rhino scope:
I was initially thinking Rhino might be related to Milbro because my early searches for info kept turning up Rhino air pellets made by Milbro. I've since seen other Rhino scopes of various sizes and styles and they seem to be their own company in the UK.
And the A.S.I type variant:
Note there is no period after the "I". The whole top line is centered differently than the version with the period.
I have two Type 1's like this.
For comparison here is the Type 2 with the full "A.S.I." marking on the Alien gun: