MR7 is VFR750RJ-L (RC30)
http://www.vsource.org/VFR-RVF_files/BHondaPCNs.htm
There called PCNs. (Product Code Number)
The Honda part format is.
xxx (Part ID) - PCN - xxxxx (the last digits usually denote revision)
ex. a lot of NC21 stuff is ML0-000 and the NC24 stuff is ML0-720, and even later NC24 stuff is ML0-721 etc.
The later stuff should fit, but is often a revised design, I take note of this with Cams / Valves etc.
To quote the website
According to the 1959-98 American Honda Motorcycle Identification Guide, the Product Code Number (PCN) indicates the "official product code for each specific model, originated by Honda Motor Co., Ltd." in Japan. Since 1966, the PCN system has also been used in the Honda Part Numbering system to indicate the vehicle for which specific parts were originally designed. When used in this context, the PCN appears in the middle section of the Honda part number (e.g., in Honda part number 50100-MT7-600, the PCN is MT7, which means this part number refers to a part originally designed for an NR750).
The PCN generally remains the same throughout the same "generation" of Honda model, but there are exceptions... Most significant for viewers of this Web site is the case of the 1990-93 VFR750FL-P RC36, which (inexplicably) has one PCN for the 1990-92 FL-N models (MT4) and a separate PCN for the 1993 FP models (MY7), even though there were no significant "generational" changes made to the FP model. When the "next generation" 1994 VFR750FR RC36 was released, the PCN changed again (to MZ7) and remained the same until the end of the generation.
It is important to understand that while the part numbers for a particular model will predominantly contain the PCN relating to that model, a significant number of its parts will contain PCNs from earlier models within the same product series—and sometimes from completely different models. Some relatively common parts (such as oil filters) are re-designed infrequently and are then used in every subsequent new model for many years. But no Honda motorcycle model has two PCNs.
The PCN is also present in the part numbers of Honda publications relating to particular models, e.g., the Workshop Manual for the NC30 is part number 62MR801; the MR8 part is the PCN for the VFR400R (NC30). PCNs are vital to an understanding of Honda parts interchangeability (also discussed here). If you're searching through a long list of Honda part numbers, the only sure way to separate the parts originally designed for your model from the rest is to search using the PCN. Doing so will leave out the "shared" parts, but those are unlikely to be critical parts such as bodywork—and it's still better than the alternative!
The following table is a listing of many common Honda motorcycle model numbers, names (nicknames) and Product Code Numbers (aka Parts Classification Numbers or PCNs). (It is the most accurate and complete chart available on the 'Web, but is still horribly incomplete——it is more complete towards the bottom of the table, however. Any clarifications or contributions to help complete this table would be welcome.)
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