Thanks for the kind words.
As you have identified yourself as the publisher of the work, the answer to your question of "how do I track and collect on the mechanical side" is where music stops being the fun and creative exercise and merges completely to the "This is a job" aspect.
You wrote or signed the deals relating to the PA that you hold claim to, it is your responsibility to manage this end of the deal. The mechanical contract that you created or signed should have a section regarding payment terms (the rate, the dates, the penalties, etc) right? If you are to get a mechanical payment and sales receipt from the record company (aka "The Label") every 3 months, then it is your responsibility to insure that happens. That means phone calls, emails, smoke signal, and yes - threatening letters from lawyers as the situation demands. You are in contact with someone at the label, right? Call them - talk to them. Ask them if accounting for the previous 3 months (or whatever your terms are) is on schedule. Quarters are the corner stone of a business's inventory, payroll, taxes, accounts payable, and general financial health.
Most mechanical sales revenue statement are only broken down by class (CDs and DPD). You won't get a list of WHO payed them the money for the CDs, etc. You, the publisher, have to stay on this, that is your job. If you wrote or signed 50 contracts, then you have 50 phone calls and emails to make at least.
In the Music Business 104 Course, the last chapter is "Advice", and this is one of things that I stress: "this is a business, and it is your responsibility to ensure that you get paid". You cannot sit back and expect all the checks to arrive on time, every time.
Remember, you signed the contract - you can make or change terms during the negotiation phase. If you are having a problem on the payment issue - then add a financial penalty to failure to comply. Also, if they are breaking the terms of the contract, the contract is null and your can revoke the permission to use the work. If it is in the contract - and if you to go there - there are legal courses of action.
Ultimately, it is your responsibility to get paid. yes, you may have the law on your side, but that doesn't mean you will get paid. Ask questions in advance. Make connections at the business. STAY IN TOUCH with them. If they have an issue, make sure they know you are on top of it - and them. Be a constant reminder to them.
Also, like I mentioned in the course - at the end of the quarter (say Quarter 1 which ends March 31), don't expect to be paid on April 1, or 2, or 3... they are probably going to hold payment until April 30. That is the "Vig" as that money that they have received as profit is making them interest, etc.
I hope this helps!