Focusers with a narrow footprint & fastening bolt pattern

[Boron]

I recently came into the possession of a 2005 8" Bresser Newtonian. It has seen better days and one of the sticking points is the focuser - a simple stock rack and pinion unit. that also has a fair amount of side wobble which is not ideal.

I've been trying to find a low cost replacement for it but drawing a blank at finding one to fit the current hole pattern, which is a Ø55mm central tube hole with bolts in a 58x46mm rectangular pattern.

Since I've never bought a new focuser before I dont know what to expect - is what I've got going to need modification and drilling new holes to fit?

[CraigT82]

Yes replacing the focuser with a better unit of a brand different to the scope, will usually involve drilling new holes. 

The central hole of yours you say is 55mm which is a bit tight for a two inch focuser drawtube. That might also need enlarging too unless you went for a 1.25” focuser - options are limited there and quality might not be any better than your original unit. There is this Svbony one which should fit your central hole, but the bolt pattern is different so new mounting holes would need to be drilled. 
 

https://amzn.eu/d/cJ2FMN6

[Boron]

I suppose out of neccessity I am then coming around to the idea of drilling big new holes in my telescope - although I remain petrified of fouling or scratching the mirrors while being simultaneously petrified of losing alignment if I remove them for safekeeping.

AS it happens that Svbony isnt too far removed from what I have already thats giving me grief. I will mark this Svbony out, though, as being only one of two focusers with technical-ish drawings available showing dimensions.

[Louis D]

Using painter's masking tape (I love Scotch Blue), temporary attach heavy cardboard covers over your mirrors to protect them from drilling swarf and other debris (falling nuts and/or bolts).  Remove them when you're done cleaning up everything.