Update existing Whirlpool Drop-in Tub

I have recently renovated my master bathroom. However, I did not replace the existing fiberglass Whirlpool tub or vanity countertops (matching). The house is vintage 1984. I changed from antique brass fixtures to brushed nickel. However, I have been unable to find replacement hardware for the tub. I am not sure of the manufacturer of the tub, or where to look for replacement hardware. There is no manufacturer label on the exterior, and I have looked through the small access panel in adjacent closet, and can see no label. Can someone help point me in the right direction? The tub is in excellent condition and I would hate to have to replace it just because the brass hardware doesn't match.

You will have to take a stem or cartridge out to identify the brand. If you post a picture of the handles someone might recognize, but the stem is the best identifier.

Unless you have a major brand like Moen which does not do a lot of internal changes over the years, you will have a very slim chance to find anything. If the previousl owner fell in love with a Broadway English Rope, or other such fancy stuff from a designer showroom, you will not be able to even repair it, much less find new trim.