Can I suggest that an Original Model 75 would be a better choice? This is a very nice match rifle, recoilless and very accurate and as your senior coach suggests (regarding weight) it has a more typical match rifle weight. This rifle sold in it's thousands as it was a very popular rifle - and this means that there are plenty of them about for sale. Tatty ones can be picked up from around £200 and tatty ones that need new seals from just over £100.
I bought a rusted and seized one for £30 without a stock and picked up a stock for another £30 but after a complete strip ( very educational) and re-blue, new internals and a lot of time re-finishing the stock with a nice new oil finish - it would have been cheaper to buy a reasonable working example for £250 - £275 - so don't rush into a tatty re-build as it may end up more expensive than you think - but lots of "fun" to work on.
Even the best ( almost mint) examples seldom fetch more than £325 so with such a wide price range there should be a Model 75 out there somewhere for you