is this car going to be a keeper as is, or do you fancy an engine swap in the future? If you fancy a better engine in the future then I'd be tempted to live with it as is, plenty of MK1 16v conversions with the above bits missing. generally the 16v will run alright with the above missing once warmed up, from cold they can be a bit fussy but rasing the idle can help. If its going to be kept as is for the long term then I would be stripping the other 16v for the proper bits. If you fit all the bits off this car back to it then it'll still be a runner after all!