Niche Cycle is a reputable company they are located in Florida U.S.A. They are a good source for genuine Mikuni parts, they are on the slightly pricey side but they stock the goods.

A VM26 is a pretty big carb for a DT100...

Pretty sure a DT100A would use a Mikuni VM22, your best bet is try to find an original carburetor that is rebuildable. Possibly a 74-76 dt100 model year would work to help in expanding your search, you can check Partzillas parts pages for interchangeability.

Yes indeed, this is one of Gr8uncleal's soapbox subjects!

Also use the European CMSNL website for this - likely to show the same data, but might include some European model info, particularly for 1980s onwards bikes.

Please note that the online parts lists aren't necessarily comprehensive - they only reflect the info that is on their databases. Still a great source for info and photos though.

doesn't sound like a good option for my wifes bike. thanks for the info.

I used to use babbitts for oem parts and info. I have recently gone to rocky mountain atv. I have found that they have more oem parts in stock so I don't have to wait the "extra" order time.

They are on eBay too.