I recommend replacing the toilet.
The average lifespan of any compact manual toilet is about 10 years...if yours is original--which is unlikely--it's nearly 30 years old. Rebuild kits (Seals, valves and gaskets) are available, but even if the toilet is more than 7-8 years old, the pump cylinder is so worn, scratched and scored that new ones won't help much...it'll work, but nowhere near as efficiently as it should. And if it needs additional parts, you're most of the way to the price a new toilet.
Thetford-Norcold has owned Wiilcox-Crittenden for several years...at the end of 2008, they discontinued the entire W-C line of toilets, including the Headmate. Parts--mostly rebuild kits--will be continue to be available for a few years, but that's all. Another good reason not to put any money into this toilet.
Most people here will agree that the Raritan PH II or PHC
Raritan PH II is your best choice for a replacment The online store here has the best price for the "conversion" (everything but the bowl, seat and lid).
Finally... you might want to check out the link in my signature...
As for the bladder...it's also unlikely that the bladder is original, 'cuz the average life of a bladder is only about 15 years before expansion/contraction and other factors spring a leak in it. You won't be happy with a bladder for sewage holding, but it has nothing to do with the operation of the toilet...so unless it is leaking, there's no real NEED to replace it immediately.
Hoses: There are only two reasons to replace hoses...1. They stink! 2. They're so old-- +/- 10 years --that they've gotten hard and brittle. So a good clue to the age of your system may be the condition of the hoses.