I see that surplus shed sells some vintage 2x barlows in 0.965 diameters. These are long barrel barlows from the past, and seem much too long to insert into the small eyepiece end of a 0.965 diagonal. Would these barlows be inserted into the draw tube of a telescope, then the diagonal is inserted into the barlow, and then the eyepiece is inserted into the diagonal?

Would these still reach focus without using any special adapters? its been 40 plus years since I tried to use one of these but I'm definitely curious how these work when using these classic 2x barlows.

Does anyone still use these and if so, is this the configuration to make the barlow work effectively?

Thanks in advance for any advice on this.

.Ralph in Sacramento.