$800 for a genuine scopeless 4t is very very cheap - in the uk you'd be looking at least at £1000+. I have seen mk1 scopes got for £550 on ebay recently which would be prefectly acceptable to use - and you could hunt out an original bracket ... or buy one of Roger's repros - which are 'authentic' in that they were actually used as replacements on l42s. I don't think you'd lose money on the set up in any case.