Thanks for the picture of 464's old tube sheets Earl. It answers a number of questions I pondered over while performing the duties of a human Q-Tip inside her. I have head two reasons for the removal of the superheaters. 1: the D&RGW salvaged them for use in another engine (or they had been removed during the last shopping). 2: The California State inspector took exception and wouldn't sign off on them. Regarding the 100PSI limit, that's fairly common with historic boilers in many states, or the MAWP is reduced by 10% as is the case in Michigan.