hfguy, WELCOME ABOARD. This is the go to place for the information you seek. I have a 53 myself and have learned a great deal from others here and now find that I can assist others and am happy to do so.
Why do you think the engine isn't correct? The 216 CID was original to these but many of us have changed to the 235 or even a 261 if we can find one. The side plate on the 216 is much taller than a 235 and surrounds the sparkplugs. Two bolts in a 216 valve cover in the center and a 235 uses four screws around the outside. I'm speaking of the later full pressure 55'-62' version of the 235. I'm not knowledgable on the earlier 235's. Also, if a 12 volt battery is present then it would need a ballast resisitor for the coil. Has the rest of the system been changed too? Instruments, lamps, etc? In any event, I'll try to run your numbers and see what I come up with.
All 53's were painted Juniper Green as standard but several other colors were N/C options. I used NAPA (Sherwin Williams) paint but DuPont and others are available in most colors for the 53's. I used a BMW color for my tanish gold interior as it matched perfectly the original paint that I still had inside. I was able to mix a NAPA paint cheaper than the 40 bucks per qt. the parts outfits want.
Good Luck and post some pictures for us.
You can check mine out at
www.picturetrail.com/Birdhtr
