This is my first Yamaha motorcycle, but I've always loved the early Enduro style bikes, and I can't wait to get mine running and ready to ride. I'm trying to find out if I need a different set of points for my 1977 dt175, or if I can use the same points that are used on 1974-76 dt175? I'm having a hard time finding any info online. thank you

Most parts lists are for US models.  And the USA did not get a 1977 DT175.  No such thing.  So pretty hard to find parts for a year model that doesn't exist here.

DMV, selling dealers, and even the sticker on the steering head can confuse what the actual year model is.  VIN is the way to go.

You'll need to check your VIN number against the lists in the Tech Library and/or post at least the first six digits or so here of the number here to ID what you have.  

vin.  2n4-00126  and thank you for the information.

The VIN number matches to a 79 DT 125 .
Someone may have done a 175 conversion previously .
Check on Partzilla for 125 Part number for ignition points , and likewise early DT 175 points .
Hopefully they match .

oh wow, thank you very much. I will do that.

 from near Salisbury, UK.

The VIN and engine number will have been the same at the point of manufacture. If the engine has been swapped over (not uncommon), then it is the engine number that you need to use to source parts for it (the engine).

Greetings from Tennessee USA 

Welcome from the Space Coast of Florida. I'd check the VIN on the neck against the VIN on the motor to see if they match, that will tell you if the motor has been swapped.