You are spot on with those expanding inserts, MGR must have got a job lot of them as no designer would voluntarily use those.
A binnacle is a fair way to cover all the instrumentation junk & if executed well is reasonable enough, but the buttock we have to look at doesn’t come very high in my favourite design list. Mind you I’m not sure what I would have preferred & as far as an injection moulded part, it isn’t complex; more plastic around the mountings front, back & the leading edge.
I adopted the fibreglass/cyanoacrylate trick, using woven banding & replaced the nylon inserts with rivnuts, also snugged in with cyano’.
By experimenting with different viscosity’s & using activator I’ve managed to reenforce all the problem places. The satin black paint I use is so close to the original that a squirt has returned it to a very convincing original looking job.
I like the use of edging around windscreen curve of the fat arse, I’ll add some to see if I like it.
M