Hello and welcome Lewis.

To start your diary: click "The Forum" tab at the top of page, click on "My Build Diary", and then click the button "+ Post New Thread".

As far as the GR-1SF is concerned, the body is basswood, so Tru-oil will work and give a very light amber tint.

I did a TL-1TB a while ago and finished the maple neck and basswood top of the body with Tru-oil only. This will give you an idea of how it should look. The link to this build is in my signature.

EDIT: Too slow again! Yes, what Simon says. I need to type faster.