Creating a new WX GUI Widget

I would like to use a Spin Control rather than a Slider in a project I
am developing in grc. I have a couple of questions-

First, has anyone developed a SpinCtrl widget and would like to share
the code?

Second, can anyone provide any advice on creating the widget my self?
The documentation I have found is fairly sparse.

It appears I would need to write
/usr/local/share/gnuradio/grc/blocks/variable_spinctrl.xml

And add 2 sections to
/usr/local/lib/python2.6/site-packages/gnuradio/wxgui/forms/forms.py
class _spinctrl_base(_form_base):
class spinctrl(_spinctrl_base):

Am I on the right track with this? And are there any other files that
would need to be created/edited?

Is there an existing widget that would serve as a good example to follow
in trying to create the SpinCtrl?

And I’m also having trouble finding what parameters would need to be
passed to the widget. There seems to be conflicting information.

Any advice on this would be appreciated.

Thanks,
George