I note that Yamaha list different coils for the 1974 DT250A (points) and DT360A (CDI) models.

A previous owner has converted my DT360A to run with points.

Are there any significant differences between the two coils used on these models?

Thanks.

Technically, there is a difference in specs, yes.  Practically?  Not that I can tell.  I've used Yamaha CDI coils with points and Yamaha points coils with CDI.  Never had an issue.  

(Perhaps that because the "energy transfer" points magneto design Yamaha used on these bikes has been described as a "mechanical CDI"?)

Thanks Mark.

i bought a coil from ebay that would not work with my points and had to use old coil. it seems like it was for 12v cdi not 6v. i would like to find a brand new coil for the 69 dt1 250 6v points if they make one?

Deep pockets?! 

YAMAHA NOS ignition coil 214-82310-40 DT1 250 1968 1969 1970 RT1 360 1971 DT GYT | eBay

Deeper pockets here in NZ because our dollar is valueless @ $588 for that coil. Anything like this below will work if you can mount it. Hope the link works.
Motorcycle Ignition Coil Assy For Yamaha FS1 LB50 LB80 GT80G DT80 DT100 DT125 DT175 DT250 DT400 355-82310-40 5G4-82310-40
a.aliexpress.com/_mPR2eFb

32 bucks

Hiya ,
I would suggest better choice is using from an original of RX series or cubs bike. The RX's i think have better sparks than the cubs ig coil.Even tho my RX still runs if using the ig coil belong to those cubs bike. The original usually comes in white color with orange wire.
issues is only the mounting holes. You could add some bracket plate for them
*All of these bike is using CDI .

Sent from my RMX1911 using Tapatalk

Can we add resistors to both the primary and secondaries to reduce current?

Gusto- Magneto ignition coils are not "6v" or "12v".  The coil you bought is either junk (like many of the aftermarket ones are) or you have a different issue. 

Emgo makes a coil many have used (including myself) and I've never heard about a problem with it.  You will have to make a bracket to mount it.  Part number is 24-71532.  $14 on Amazon.