Really glad to hear that you recognize the importance of B2B branding and I hear your frustration at not being able to explain to your colleagues and seniors. The trouble is that for too long brand-building has been associated with advertising and therefore seen as the domain of B2C firms. In truth, branding is even more important for B2B players because their offerings have become increasingly commoditized. Not possible to give you a marketing strategy off the top of my head :) but here are some thought-starters:
1. Draw up a list of all the audiences you want to influence. Go granular. So for example, in your OEM customers, in addition to the department that places the order, is there someone else whose opinon matters? In the after-sales market, mechanics are very important influencers. Be sure to include them.
2. Define why each stakeholder should choose your brand over the competition. Low price is not an option. This is tough but you must find a clear, credible answer.
3. Now for each of the customer groups, define their pre-purchase, purchase and post-purchase journey. For each leg, identify possible points of interaction with your brand. For example, in pre-purchase ask what publications do OEM customers read? Is there an industry body to which they all belong? In post-purchase, ask how you stay in touch with these customers, even if an order is not immediately forthcoming. Defining what you do at each possible point of interaction will give you the foundation for your marketing strategy.