Need Databse Help, Will Pay.

I have an inventory database i am working on but am too new to access to know all the inner workings. Quick summary of what I need to accomplish:
I have a databse with several tables each representing different types of parts that we sell. Each table is similar in that the primary key for each is the part#, beyond that though the different types of parts have different specs that go with them. (example: for enclosures, the dimensions are needed but the amperage is not, for circuit breakers the opposite would be true.)

Next I have an inventory table, each record has a unique Control number that we assign as the primary key, then just a part #, notes about its condition (some parts are used) , a shelf location, and a price and date.

I have a very small sample database that i can email to anyone interested in looking at it.

Basically what i think i need to come up with is form that has several aspects to it. A user enters a "CATALOG NUMBER" into a combo box at the top of the form. tabbing out of that field then shows the specs of that catalog number below. the problem is the part numbers would come from a number of tables like the BUS PLUGS, MCCB'S, ENCLOSURES tables, all of which have different types of data. Finally, at the bottom of the form would be a result of a search through the INVENTORY table returning the multiple lines of line by line data where the CATALOG NUMBER matches the one specified above to show the records with the same catalog number but different notes, prices and different shelf locations. anyone care to take a look?