There really isn't much to include. There is no special tax treatment for a 401k withdrawal used for that purpose. That is not an exception to the penalty for early withdrawal, and the withdrawal is fully taxable as ordinary income.
The purchase of a new personal residence,either primary or secondary, is not a reportable event.
You can deduct mortgage interest, points, and real estate property tax paid at closing. You report those expenses along with other mortgage interest/property taxes paid in the year at
Federal Taxes (or Personal if using Home and Business)
Deductions And Credits
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My Home
All other costs paid at closing, including transfer taxes, "stamps", escrow fees, etc., are NOT deductible from current income, instead you add them to the cost basis of your home and you will get the benefit when you sell.
You likely did not pay real estate property tax on your mobile home, but you may have paid personal property tax, that is deductible under Cars and Other things that you own.