No carpenter needed - if you have a saw and a drill, that's all you need. If you are not confident with a saw, your local 'bunnings' type hardware store could have a cutting service. Many timber yards do too. Or ask a mate over, ask him to bring a saw and his drill, and offer him a beer or two for 10min work. All you would need is a few bolts, washers and wingnuts. For me DIY needs to be easy,
Yes, your dobbie is really only suited to afocal photography. It is a fine instrument, but not for loading a camera onto it.
There is one other option you might like to consider before you splash out on a new scope:
Adding a webcam to your telescope
This little webcam won't test your dobbie weight wise. But it will allow to attach a camera straight onto it. Tracking isn't necessary either - the software that is linked to in the article will correct for drift. Adding a barlow is no problem either,
You have a computer, and if you don't have a webcam as noted in the article, they cost bugger all, and a mate could have one lying about doing nothing you could get for nix. I made one of these little webcams too, and are blooming brilliant! Used it with my dobs too. The pics below a just single frames, no stacking or other post processing. The webcam drivers will allow you to vary exposure too which is necessary to bring up Jupiter's moons. These were all taken with my 17.5" push-pull dob - no tracking here. The pics were taken a few years back, you can see this as Saturn's rings are very shallow here.
On eBay, you can also find nose pieces that attach to the webcam and fit into a 1.25" focuser,
Webcams today are a bit of a forgotten tool. They are still very powerful and for some people provide all the astro photos they need.