Thanks, you are right, now Mamod engines come with a center flue/gas fired poker, which is a big improvement over the older style meths' burner.
The 400E in live steam would be a show stopper...finding a body shell would be one way to go. My 259E shell was found on ebay for $12, however, finding a cheap 400E may be tough. But the final product would justify the expense, imo.
Joe