Progress! I dug a little deeper, and here's what I found. You may want to settle in and get comfortable, this could take a while….
Am looking at V8 not 4cyl in the manual. The 44.05 diagram and parts list are for pre-2000MY V8. The manual I have shows the 44.05 pages and also a 44.05a parts list that is applicable to USA 2000MY V8, but it's missing the 44.05a diagram. Apparently someone skipped a page when they were scanning the manual or Lotus was just deficient in their pubs dept, probably the former. After much digging I finally located the 44.05a diagram, image is at the end of this post.
Service notes section EMM2V describes evap system theory of operation and shows the pre-2000MY canister location with its protective cover in the LR wheel well. See attached EMM2V pages.
It turns out there are several differences between the pre-2000MY 44.05 and the USA 2000MY 44.05a. Where the earlier cars have a cylindrical evap canister (44.05 item #1) with integral purge solenoid, the later cars have a rectangular canister (44.05a item #4) with separate purge solenoid (item #10). Also the mounting locations are different. In either case, the purge solenoid when activated opens a port allowing vapor to be drawn from the canister to the engine intake plenum (via the EGR manifold).
Item #22 on the 44.05 parts list is the canister vent close valve, which is mounted on a tab near the engine bay fwd bulkhead upper left side as shown in the EMM2V illustration. The vent close valve is item #7 on the 44.05a parts list, although they are identical part numbers. This valve allows the flow of fresh air into the canister to assist purging, or shuts it off as needed.
Evidently starting with USA 2000MY the canister was changed as well as moved from the wheel well to the area outboard of the LH air filter housing. It's the black box with 3 hoses attached to the left in the first photo below, aft (left) of the round vacuum reservoir, seen through the access panel inboard of the LH rear quarter window. Second photo shows the separate purge solenoid mounted on the tab that is attached to the metal header rail along the top of the engine fwd bulkhead near the center. The last photo shows the solenoid and tab, the non-return valve (NRV) between the 2 white clips, and the hose leading to a grommet where it passes through a bulkhead to connect with the canister. Also the canister vent close valve is visible below the NRV and behind the LH cam cover breather hose.
Just FYI the link below has factory pics of the last V8's during buildup on the production line and these help show the later configuration (excellent resource site BTW!!):
A Photographic Build Record of the Lotus Esprit V8
www.espritv8build.co.uk
Also found an update package for the service parts manual although it is applicable to a later version of the manual than what I have currently:
From a documentation standpoint I think what I really need is service parts manual N082T0325J which covers the 1996-2004 V8, together with the corresponding latest service notes manual. Then along with the update package it would be a fairly comprehensive set.
Turns out the hose I reconnected to the RH air filter housing is the RH cam cover breather vent (pic below), it is item #17 on diagram 42.01. Not completely clear to me how this would have triggered the evap leak code 0442, but I guess it's possible since ultimately it ties back in to engine areas that are also connected to the evap system.
For anyone that hasn't nodded off and is still reading there is an end to this saga I promise. Getting back to the original noise issue (which I almost forgot about in digging through all this), I confirmed it is the purge solenoid. It slides onto the metal tab that is bolted to the aforementioned metal frame rail along the upper fwd engine bulkhead so it makes sense that rapid repeating "clicking" noise (kind of a thumping actually) is transmitted to the cabin. Plus the bracket attaching hardware was slightly loose, adding to the percussion symphony. Anyway I inserted a washer between the bracket and the rail which helps prevent actual contact between the solenoid and the rail, then snugged it up. Still can hear/sense it but it's softer. Seems to me this design is abusing not just my ears, but also the poor solenoid by constantly cycling it so rapidly...hey at least it's an easy replacement if it ever fails. Again, it's better now and maybe at some point I'll try a more involved isolation measure. Or just chalk it up to the fact that she is continually informing me of system functionality i.e. I know when we are purging. Not that I particularly care to know.
To maneuver the solenoid during this exercise I had to temporarily disconnect the hose that leads to the intake plenum. Upon engine start I got…wait for it….a CEL !#/@?&! Codes were the familiar P0442 Evap System Small Leak and a new one, P0108 MAP/Baro Pressure Circuit High. Reset the codes and did a test drive - no codes. So I suppose just disconnecting that purge/plenum hose for a short time (yes the engine was NOT running) triggered the fault. All good for now, will continue to monitor the situation.
Thanks for the assist and for tolerating my diatribe. Hopefully it could help save someone a couple steps if they encounter a similar situation.