Good day...
I'm trying to get a "beater" 1974 Dt 175 A back in service for off-road use only...so cost is an issue.
Does anyone have any experience they can share re: the cheap-made-in-China pistons now offered on Ebay?
Any advice is appreciated...thanks

Stay away!  There is a post from Enduronut on the topic...  someone used one and it quickly failed and did a lot of damage in the process. 

You can slightly modify Yamaha Blaster pistons to work...  just file a little off the skirt length.  Quality ones are available fairly reasonably priced.

Chinese ones are a waste of time. don't even try.
if you want to cheap out, a modified Blaster piston from a name brand like Mark suggested works reliabily. Sometimes Pro-X blaster pistons are on eBay for 50-60$ and they come with rings and a good wrist pin

Thanks for the feedback.
Fact is, I'm not sure I know what a Blaster is!
When I do a search...is there a year? engine size? etc?

Is this what I'm looking for?

Pro X 01.2281.000, 66mm bore
Ebay listing: 144036634658

Yamaha Blaster ATV Quad...  made from about 88 into the 2000's... the engine is a direct descendant of your 175...