*****DO SO AT YOUR OWN PERIL*****
This is very left-field, but here goes:
Go to Wal Mart/Canadian Tire whatever, find some punks that don't care about their job, ask them for some blank invoice paper for $$$.
OR
You could make some fake stationary of some place that has gone out of business using a laser printer. I have no idea on what to use as paper or how to get 'invoice-like' paper.
Then take whichever invoice paper you have and feed this into a DOT MATRIX printer to fill in the blanks/details, Make, Model, Date, License #, Materials, Labour, GST, GST#, etc. You might want to compare with a real invoice so you get all the little details right.
If you have a real invoice paper, you cannot manipulate the fields, so make sure you have at least a dozen papers to practice on, you're gonna have to get the spacing just right. If you made your own invoice paper and it's decent, you can adjust the fields to fit your dot matrix printout.
This is just a somewhat viable alternative from "experience"
Doing something like this can be considered fraud, so if you attempt to undertake any of the above-mentioned, I take no legal responsibility for yours or anyone elses actions.
*****DO SO AT YOUR OWN PERIL****
"All these years I thought it was power that brought responsibility. It's not. I was wrong. It's responsibility that brings power. It's knowing what needs to be done that brings strength. And courage." - Peter Parker, Earth X