Hello Moe,
I personally own a 1966 Coronet 500 2 door hardtop and have owned a 1966 Coronet 440 2 door hardtop and a 1967 Coronet R/T 2 door hardtop in the past, so my experience is with the 1966 and 1967 Coronet models. I will need to let some of our other members here on the DCR who own 1965 Coronet models answer any specific questions you might have for your model year, as there were many changes to the Coronets from 1965 to 1966.
While I do not have access to a 1965 Coronet Factory Service Manual, I was able to find a couple of pages from the 1965 Plymouth Belvedere and Satellite Factory Service Manual regarding front bumper mounts and they do show the 1965 Coronet there as well, so maybe this will give you some additional views on how this assembly is mounted.
Some model codes that you will see on these two pages are as follows:
AV = Plymouth Valiant models
AP = Belvedere and Satellite models
AR = Coronet models
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Here is a picture of the Chrysler approved and licensed 1965 Coronet Factory Service Manual in the CD format that I will give you an Ebay auction link to below. This manual also includes all of the 1965 Dodge A-Body and C-Body cars as well as the 1965 Coronet B-Body models.
An Ebay auction link to purchase the 1965 Dodge Factory Service Manual in a CD format from Faxon Auto Literature which is licensed by Chrysler as I mentioned.
http://www.ebay.com/itm/161247021736?_tr...EBIDX%3AIT
Faxon also offers the 1965 Factory Service Manual in a printed book format which includes just the 1965 Dodge Coronet and 1965 Dodge Dart models.
http://www.ebay.com/itm/361051964523?_tr...EBIDX%3AIT
Here is the Home Page link to Faxon Auto Literature's website if you'd rather purchase the manual directly from them as opposed to an Ebay auction. This will also give you a chance to see what other items they sell for your Coronet.
http://www.faxonautoliterature.com/
I hope this helps and hopefully some of our other 1965 Coronet owners will chime in here and will offer you more specific advice than I'm able to.
Richard