Few notes on grammar:
* You don't give a quote, you give a quotation.
* There is a hyphen in no-obligation when it is used as you used it: Free no-obligation quotation.
* There is a hyphen in one-off when used as you used it.
Yes, I know it's fussy, but so are quite a few of your customers.
And get it spell checked and proof read by someone you trust who has an eye for detail.
Yes, put phones numbers:
Office number:
Mobile number:
Email:
I'd avoid putting your address. You might put something like;
Fred Bloggs Window Cleaning Inc
cleaning windows in and around Cheltenham
I'd agree with dropping the line in red as well. Most people will simply scoff at it.