BiBiBiB .... it is probably worth getting the jetting/choke info from the weber in question ( I assume a 45?)
I am a bit confused ... you say you ran it two or three times for putting away and have only now brought it back out ( which seem like very few real kilometres) and you also say engine written off after 10k km ,,, is that 10 000km?
Probably not what you want to hear but having 10 000km worth of possibly extremely rich running and significant bore wash isn't a good look or feel, especially when you felt it wasn't going right power wise. ( I don't know how long it takes for bore wash to occur but there is a good reason a number of people basically take the car straight from heat cycling and start up to the dyno/rolling road)
I have a 1360 road motor, but it has head and valve improvements over standard, and i have had it running really well on a weber 45 on the track, but for street use it started with twin HS4 SUs and now currently runs a single HS6 ( a Hif44 would have been good too). Both the SU setup runs well.
I have found it much harder to guess a safe starting jetting on webers (others with more knowledge can offer advice on the webers, whereas i could confidently say twin HS4s running #6 needles or equivalent or a HS6 or HIF44 with standard needle will safely start you up and get you to a rolling road or at least someone with a wideband AFR meter.
and finally - it would be prudent to look at the whole unit now - that way you will know the gearset used the diff ratio, whether you have a centre oil pickup etc and also it is much less problematic seeing and replacing a worn diff pin, or get a thread helicoiled now rather than roadside somewhere down the way.......
Best of luck