Create custom part based on generic one

Hi all,
I am trying to create a custom part (stripboard PCB) based on the generic one.
The difference with the generic PCB is that the one I got (50 units) have a strip pattern linking 3 consecutive holes then cut then another 3 holes etc.
I can modify the original one to get the needed pattern but doing this every time is a waste of time.
I tried to store in My Parts bin the modified part but it only gets the outside dimensions but not the strip/track pattern.
Is it possible creating a custom part based on an existing one?

I think strip board is going to be hard. Parts factory generates the svgs on the fly. It should be possible to capture a configured strip board (by grabbing the underlying files), and make a custom part, but that would only give you that particular layout, and not allow further changes to the strips when reloaded unless we can fool parts factory in to accepting it again (and I expect that to be difficult, because I expect it recreates the entire strip when you make a change.)


Thanks Peter.
As a workaround I am copying the edited part from the first document I created and pasting onto a new document seems to do the job.
I thought I could add a custom modified part already on a sketch to “My Parts” bin but when I move it there it loses the strips customization only keeping the modified size.
Anyhow I can live with the copy & paste from a previous sketch.
Thanks again