If a proposal, a website or a brochure can generate a contract or a sale, then a company does not need sales people.
Sales people often complain about their marketing materials--they are not current, not visual enough, not digital, wrong case studies, wrong information, and so on--as if they can't sell without them. A constant battle I hear in companies is over the quality of the leads that marketing generates. There is often an undercurrent of complaints as to why sales are not higher by sales people aimed against marketing. Maybe all of the commentary is true. No doubt it is frustrating. However, it is a terrible excuse for why a sales person can't get a sale or even generate a lead.
Don't let bad marketing materials get in the way of generating new leads or sales. If marketing materials could sell something then it wouldn't be called "selling," and your company wouldn't need sales people.
Here are a few things you can do:
Do you need pictures of products, examples, materials, people, whatever? Take them. You have a smartphone, use it. If you have done a good job talking about your product or case study, then the pic doesn't sell it, the pic confirms what you have described.
Next time you are with a happy customer, use your smartphone or a flip video camera to record a two minute interview testimonial. I have done this with transactional customers up to CEOs of billion dollar companies--it is easy and can be fun.
Send out a three question survey to your best customers: What was the problem you were having when you hired us? What did you like about what we did for you? Why would you recommend us? Use the answers as a list of quotes when people ask for a description.
This is a topic covered in greater depth other places. Let me just offer this one addition--don't wait for marketing to generate your leads. One of the great sales people that I know generates all of this own leads, sources his databases, crafts his own email and letter campaigns, tweaks his messages...even though he has a marketing department. He told me, "When I start the conversation in my voice through those outreach campaigns then the conversation is heading the way I want it to go from the start."
I rarely speak with a company that is not either re-doing their website or preparing to re-do it. This has become the favorite excuse of organizations as to why they can't sell--our website stinks! Really? That's the reason? If you are a sales person, then a website does not sell for you. It provides an easy access point for information for prospects, it might create a touch-point for first time prospects to find you and it is possible that some of your case studies or testimonials are posted there--but it does not sell, it just helps.
Marketing materials can make your job easier, but they are not your job. Your job is selling.